LOS ANGELES -- California's newest museum, and Armand Hammer's latest bid for immortality, won't even open until Nov. 28, but it's already under siege. The art world is livid, the press hostile and one relative so enraged she is suing for most of its art.

But here it is: the Armand Hammer Museum of Art and Cultural Center, all 79,000 square feet of it, plunk at the corner of Wilshire and Westwood boulevards.

"You can't drive by without seeing it," says Dick Sherwood, one of many Los Angeles County Museum of Art (LACMA) trustees whose blood pressure doubtless still spikes at the sight.

Until three years ago, Sherwood and other LACMA trustees had every expectation that Hammer's 100 master paintings, the best among them by Rembrandt and Rubens, van Gogh and Gauguin, as well as his 10,000 Daumiers and his Leonardo da Vinci manuscript, would eventually come to their museum, as Hammer had often promised.

In January 1988, however, three months after a nasty confrontation with the trustees over where and how his art would be displayed, Hammer shocked the museum community by announcing he was not giving them his collection after all and would build his own museum, to open in November 1990.

"They gave me an ultimatum. Imagine it!" says the 92-year-old Hammer.

Many assumed -- and LACMA supporters doubtless hoped -- that no museum could possibly be conceived and built in 34 months, and that Hammer, at last, would have to back down or fall on his face.

They were wrong.

But last summer disaster did loom, as lawsuits threatened to derail the museum. One, on behalf of Joan Weiss, sole heir of Hammer's wife, Frances (who died in December 1989 at age 87), is seeking more than half his fortune, including most of the art the museum is being built to house. Three other suits, launched by angry stockholders of Occidental Petroleum (of which Hammer is chairman and CEO), protested that the museum was being built and endowed with $96 million of their money, which they saw as an unauthorized use of corporate funds. Those proceedings held another surprise: It was revealed that Oxy had paid for some of Hammer's art, notably the $6 million Leonardo manuscript he renamed "Codex Hammer."

The challenge from the heir to his wife's $17 million-plus estate has been emotionally devastating to Hammer, according to colleagues, and is still in the discovery stage. In the Oxy cases, however, a Delaware judge approved a settlement in which Oxy had the right to build the building, but could not spend more than $60 million. It also capped Oxy contributions to Hammer-related charities.

The judge's ruling approving the settlement is now being appealed. But for now, due to the cutoff of funds, the Hammer will open with most of its ground-floor, "cultural center" facilities unfinished.

Meanwhile, Hammer is getting the last smirk: Three thousand "save the date" notices have been mailed to invitees, making clear to any doubters that the opening will take place on time, and that he hasn't lost his sense of humor. The announcements take the form of a court summons: "Let the record show that you are requested to set aside the month of November on the twenty-sixth day ... for your attendance at the official dedication and gala celebration of the Armand Hammer Museum of Art and Cultural Center ... IT IS SO ORDERED."

On the front of the notice is one of Hammer's Daumiers, titled "The Pleading Lawyer." As a measure of the museum's troubled birth, so many lawyers are involved in related litigation that a preview opening has been arranged just for them.

The Breakup "I had never intended to have a museum," says the pale, thickly bespectacled nonagenarian, as he settles down to an elegant lunch of linguine and clams in Occidental's 16th-floor executive dining room. Nearby, frame-to-frame in the corridors, stairwells and boardrooms, Hammer's travel-weary art collection awaits its final resting place in the museum's galleries.

"I intended to give my collection to the L.A. County Museum and give my drawings to the National Gallery," says Hammer, as he wolfs down a dripping clam. "I made a deal with {National Gallery Director J.} Carter Brown -- I wanted to be sure my drawings were kept together: Not many people have ... the triple crown, as I call it -- a Michelangelo, a Raphael and a Leonardo ... " It was a collection formed with the help of, and promised to, the National Gallery.

"So I told Carter Brown what I wanted. ... I wanted it clearly understood that they'd keep it all together. He agreed to it if I'd put up a million dollars to buy this big Raphael drawing... . He's a pretty good trader," says Hammer, "so I did.

"So he got the whole lot of my drawings, including a wonderful Durer, a beautiful 'Cowslips,' and for the first time, he built a gallery within a gallery -- the Armand Hammer Gallery. We sat in the VIP lounge at National Airport: We had to get an answer yes or no right then and there... . It was cheap at a million dollars."

Brown says Hammer could see it that way. "We said there'd be a sign that would bear the name 'Armand Hammer Collection,' but we don't name pieces of the building." Brown says that so far 12 drawings belong to the gallery, with 39 "contractually to come one year after his death." He added, lawyers on both coasts have assured us" that the agreement is binding.

The L.A. County Museum, however, was asked for considerably more, and its board decided to play a less patient game with Hammer. There are many accounts, no two alike, about what ultimately tore the deal, but it surely ended after a 39-page legal agreement, which would have superseded all earlier agreements, was presented by Hammer to the LACMA board in August 1987. It demanded what the trustees viewed as a museum-within-a-museum (with its own curator, a study-center director and board), an arrangement the trustees felt they could not countenance.

In the end, a sense of outrage and betrayal consumed both sides. Each felt that long-standing promises had been broken. The museum did not sue, says attorney Dan Belin, LACMA board president, because it did not have a binding contract with Hammer. "I think he had a moral obligation -- it was not enforceable -- and I think he broke it."

"The understanding," says Hammer, "was that ... a whole floor -- the upper level of the Hammer building {at LACMA} -- would be dedicated to my collection, which would be all together. I guess it was written, wasn't it?" he asks his longtime aide Hilary Gibson, suggesting a lack of attention to crucial details that Belin and other opposing lawyers say is a frequent Hammer tactic.

"Sure," replies Gibson, now director of development for Hammer's museum, without whom, Hammer says, "there would be no museum."

According to Belin, no such deal was ever put in writing.

"When Ken Donohue was director, everything went fine," says Hammer. "Meanwhile, the L.A. County changed the board and put in a new director named Powell, and a new crowd got in charge of the museum that believed in modern painting, which I don't collect." Earl A. (Rusty) Powell III was appointed director in 1980.

"So somebody told me that they had sold spaces on the floor where my paintings should have been to anybody that would give them $100,000 to $250,000, and they had their name above my paintings," says Hammer. "I attended a meeting of the board, and I said to the director Powell and to Mia Frost {Camilla Chandler Frost}, one of the owners of the L.A. Times ... I said I saw the names up there, and that was contrary to our agreement. Then they gave me an ultimatum... . They said they couldn't take down the names. They thought I had no place to go. But I did have a place to go: I built my own museum.

"I thought it was a pretty shabby thing to do," says Hammer. When the LACMA deal fell through, Hammer considered giving the paintings to University of Southern California, to which he had already given nearly 50 paintings some years ago (some of which he has borrowed back and is now trying to buy back or reclaim permanently -- another source of outrage in the Los Angeles art community).

Gibson didn't think much of the USC idea. "I came over here one night and looked around the building and said to myself, 'There ought to be a place here at Occidental for this.' " Then she spotted the gas station and parking lot next to the Oxy building and decided it was perfect. "It seemed the most natural thing to do," she says. Within days, the plan for a museum grafted onto Oxy -- both physically and fiscally -- was underway.

By Jan. 7, 1988 -- just three months after the final LACMA confrontation -- architect Edward Larrabee Barnes, renowned for distinguished museum buildings at the Walker Art Center in Minneapolis and the Dallas Museum of Fine Arts, was hired. "The basic design," says Gibson, "has changed very little from that first concept."

The Building in Process Hilary Gibson is leading a tour of the building, which comes as a complete surprise, given its cold exterior of black-and-white-striped Carrara marble. Inside, it is a warm, welcoming urban oasis, with a tree-filled courtyard at its core. Surrounding the open courtyard is a modestly scaled two-story gray-beige stucco structure, with wide, nobly proportioned arched loggias.

Upstairs, on the museum level, the loggias lead into the state-of-the art, ingeniously skylighted galleries, where the permanent collections and temporary shows will soon be installed. At ground level, around the courtyard, are the facilities that, when completed in 1991, will make up the "cultural center" component of the building -- the 248-seat auditorium, restaurant facilities and courtyard cafe. A Leonardo/Daumier library and study center is also planned.

"It's very like Italy," says architect Barnes. "You come into the building and you're outside again -- you're always doing that as you go from one space to another via the loggias. I think it's going to do something for museum fatigue. I think after crossing that landscaped courtyard with trees, when people leave, they'll feel like they've been somewhere."

Until the amenities are complete, and visitors can sip cappuccino before a concert, performance or film, the biggest draws are likely to be the temporary exhibitions, starting with the Kazimir Malevich show, now on exhibit at the National Gallery of Art -- a show made possible because of Hammer's close ties with the Soviet Ministry of Culture, and for which the Hammer staff produced the catalogue. No other exhibitions are yet scheduled, though shows of ancient Chinese jade and colonial paintings from Cuzco in Peru are said to be in the works.

The museum level also has a small permanent Daumier Gallery -- where rotating groups of prints, drawings, paintings and sculptures by this 19th-century French artist and his contemporaries will be shown -- and an audiovisual orientation gallery. And reflecting Hammer's reverence for his Leonardo Codex, there is a stripped-down, Romanesque chapellike space built especially to house it.

The wild card is how the pieces in Hammer's eclectic, uneven collection -- these 100 paintings by old masters and 19th-century masters -- will look when they are finally installed.

But therein lies the true genius of Barnes's plan. For he actually capitalizes on what has long been seen as the central problem of Hammer's art collections: that they could not sustain, in size or quality, an entire museum. This building tacitly accepts that fact by creating what is, in essence, not so much a full-blown museum as an urban cultural center with an art gallery on top.

Who's on top when it comes to the organizational chart, however, remains a mystery. There are presently three directors, but no one in charge: Hilary Gibson is director of development; Stephen Garrett (formerly of the Getty Museum) is director of construction; and Alla Hall, a former research associate at LACMA, is director of art.

"Hammer is in charge," says Gibson. "He runs this place like a feudal court."

She is aware of the potential for chaos, but shrugs. Under another name -- Martha Gibson (maiden name) Kaufman -- she worked for Hammer for 17 years, first as the high-profile curator of the collection, and for the past decade as a low-profile researcher and consultant. A year and a half ago, she surfaced in her new role, having legally changed her name and leaving many wondering who this well-placed newcomer might be.

A tough, bright woman from Ashtabula, Ohio, who met Hammer while interviewing him for an airline magazine, Gibson says there's no mystery about it: She changed her last name after her children were grown and her husband remarried. "For the same $1,500, you could change both names, so I did: I've always hated Martha and loved the name Hilary."

Walking outside the building for a photo session, Gibson gently took Hammer's hand as he wavered slightly on the bumpy sidewalk, and their fingers slowly wove together. Old friends, surely.

Art and Artifice Though Hammer's benefactions are scattered all over the globe, problems at home threaten the museum. Joan Weiss, his wife's sole heir and niece, has brought a lawsuit that could strip the Hammer Museum of more than half its art, and Hammer himself of more than half his fortune.

"I think it's a matter of greed," says Hammer of the pending Weiss suit, which claims $400 million in community and separate property rights, and could leave the museum bereft of its art.

"This doesn't have to do with my greed," says Weiss. "It has to do with Armand's greed. He's projecting it onto me. It's not Armand's money: We're talking about Frances's half. It was her money.

"I just feel that his intent is to perpetuate this image he's created of himself by having the museum. It's to satisfy his ego and his sick greed. I don't feel that Armand Hammer is a deserving charity, and I feel very strongly about that."

The Future Major problems still confront the Hammer Museum, apart from the Weiss suit: the matter of raising several millions to finish it (a Japanese firm has been approached for $13 million), of rousing community interest to support it, of organizing a staff to run it.

But why doesn't Hammer kick in some of his own money, especially when he speaks with such glee of spending $3 million in one night at Sotheby's London auction house in July, acquiring 12 English paintings of "beautiful ladies" for an exhibition he hopes to have of "all the beautiful women who've ever been painted?"

"Rich as he is," says Gibson, "most of his money is tied up in the Armand Hammer United World College, 'Stop Cancer' {which funds research} and art.

"Also, his basic feeling is that the museum should be run like other museums, with fund-raising and community support," says Gibson. "But I think we'll get it when people see what they have here."

Thanks to Occidental, the museum will be born rich. Hammer explains: "Oxy has set up a $36 million endowment for the museum, which will yield $5 million the first two years for start-up funds, $4 million for the next two years and $3 million for each of the next 27 years. So nothing could really ever happen to the museum."

The farsighted plan also provides that, after 30 years, there will be a $55 million residue in the endowment with which the museum could purchase the entire complex, including the Oxy building to which it is attached.

Additional income for the projected $3 million annual budget, after the opening year or two, will come from memberships ($20 and up), from admissions ($4.50), and from sales in the large gift and book shop, a joint venture with New York's Metropolitan Museum, which Gibson calls "Metwest."

"With his luck, we figured we'd strike oil when we dug for the parking facility," says Gibson. Instead, in drought-stricken Los Angeles, they struck drinkable water, which Gibson plans to bottle and sell in the museum shop.

Winners and Losers The community of Westwood is the big winner here. "The local merchants and the people who live here and at UCLA are thrilled," says Hammer.

But surely the complex as a whole, offering a sense of place in this place with no center, is also a greater gift to Los Angeles than one more floor, or wing, at the Los Angeles County Museum. If it works, old animosities will eventually dissolve, and the Hammer will take its place among the many new arts entities now blossoming in Southern California. If it fails, there will be many to rub their hands with glee and call it justifiable revenge.

"We're unhappy but philosophical," says LACMA's Sherwood.

"I'm overjoyed, in 10th heaven," says Hammer. "I'm so happy that I can have something to say about how my own paintings will be shown."

This is not, he says, his "ultimate monument... . One of my aims is to find a cure for cancer, and the Julian and Armand Hammer Building at my alma mater, Columbia, is doing great work in cancer treatment. The Armand Hammer United World College also: If you're going to have peace in the world, you've got to start with young people at an impressionable age -- they've got to learn to live together.

"The museum," he says, "is different. My conscience tells me it's correct, and I don't care what people say."

His Herculean efforts to get it built, however, suggest that he does care, and deeply. They also bring to mind a story he recounts in his biography, and, to this day, recalls as "painful" and "terrible." It is about an old man he met when, at age 23, his first millions under his belt, he was making his first journey through famine-stricken, post-revolutionary Russia.

"I was walking on the road, and we saw this old man sawing wood planks -- by hand. You know how tedious that is; he had to cut down the trees himself!

"So we stopped and said, 'What are you making?' And he said, 'A coffin. I just have enough food to last a few months, and I want to be sure I'm not buried like a dog.' "

Surely Hammer is expending no less effort to ensure that it doesn't happen to him.