The buses start arriving at Mickey Rooney's City Line Dinner Theater at 11 a.m., disgorging loads of senior citizens on a matinee outing: The West Side Senior Citizens, St. Mary's Golden Agers, worried about getting their tickets and getting settled before the 1 p.m. show of "Forty Carats," starring Terry Moore.

Yes, Terry Moore, once one of the pop-cultural icons of the 1950s, the girl next door who looked good in a bathing suit and spike heels. Now she's thinking about changing her billing to Terry Moore Hughes, to link her for perpetuity to "the love of my life," billionaire Howard Hughes. "It is my legal name," she says. Her shipboard marriage at the age of 18 (15, according to some accounts) to the then-43-year-old Hughes has recently been acknowledged by his estate and an undisclosed sum settled on her, thrusting her happily into a spotlight her manager, Jerry Rivers, predicts will "renew her celebrity."

And the dinner theater? It's all part of "the scheme." Their scheme to get her working again, to land the book deal and the movie deal, to get her on the talk shows and then the television series and the movies, then the telethon for her charity ("I hope to eventually have a bigger telethon than Jerry Lewis," she says), and who knows what else? "There are some very big things happening for Terry in terms of p.r.," says Rivers, a fast-talking former New York garment industry businessman.

Meanwhile, Moore, sitting before her dressing room mirror in preparation for the evening's performance, is rolling electric curlers into her ash blond hair and thumbing through the National Enquirer. She stops at a picture of actor and playwright Sam Shepard and shows it to Rivers. "This is the actor I think should play Howard," she says. "He looks so much like him."

Moore, according to "The Film Encyclopedia," is 54, but somehow in print her age has ended up as 51 or maybe 52, sliding down graciously while no one's looking.

Her face shouts against time. It is the face of a woman determined to defy wrinkles and bags. But they lurk just beneath the surface, ready to appear at the first sign of inattention. As she talks she gently presses a nascent jowl with the tip of a well-manicured finger, pressing it back into her cheek as though it might disappear.

She can easily pass for the 40-year-old she plays on stage in "Forty Carats." Her publicity pictures present a woman of about 30, and she doesn't blink when flatterers tell her she looks 25. Last year she posed for pictures in scanty, low-cut lingerie for Oui magazine, photos her manager declares are the best ever taken of her. ". . . I am as firm as I was at 18," she said in the accompanying interview, attributing this mammary longevity to Hughes' insistence that she always wear a "double-strength bra" for exercise, and a regular one when she was asleep.

Turning 40 was "the horriblest thing" for her to face. It came at a low point in her life, when her 12-year marriage to millionaire Stuart Cramer had ended and, for the first time in her life, she had to cope by herself, with two children to take care of and barely two diamonds to rub together.

"It was the first time I hadn't had servants," she said, her big eyes shining with seriousness. "I had been a movie star since I was 8 years old, I'd always had everything taken care of. I'd never even had to mail a letter myself, and suddenly I was like everybody else. I went from yachts and racehorses and airplanes to worrying about how I was going to pay the bills every month. Suddenly I was in the mainstream of life, and it was sink or swim. I survived."

"Wait," says Jerry Rivers, "There's something you should understand. When she says everything was tough, tough to Terry didn't mean she didn't have money . . . She means she didn't have all the servants. But she lived in a beaut-i-ful home in Brentwood, which she bought with cash--"

"But it was like a crackerbox to what it was compared to," Moore says.

"What she considers a crackerbox is--if you told 500 families that your punishment for this crime is that you have to live in this house for the rest of your life, they'd say, 'My God, why didn't I commit this crime earlier.' For Terry having one Rolls-Royce, one limousine and one Mercedes was not the way to live, because she was used to having 13 thoroughbred horses and stables. She sold the house to Steve McQueen . . . Terry considers being down to $2 million is being broke, because her money is at a stockbroker, or in a bank in trust."

"But I thought I was broke," she says. "You see these bag ladies walking around New York and then they die and you find out they have so much money. I mean that's what it was like in my head."

The five years after her 1972 divorce from Cramer were what she now calls her "morgue period." She finally realized that what she wanted to do more than anything was work.

"I was coping, but until I met Jerry I didn't have any direction," she says. There was another problem: nobody took her ambitions seriously. Except Jerry Rivers. They met in New York under circumstances they will not reveal because they are writing a screenplay about it.

"This, you might have to live it to know it," says Rivers. "Terry travels in a social circle in California that is black tie dinners, senators, governors; her best friends are the people that run the biggest companies, both industrial and motion picture--"

"Heads of state," she interjects.

"The so-called big shots of the city," he continues. "She gets invited to the Kentucky Derby every year, private jets come pick her up. So when she says she was unhappy, I said, 'How can that be?' She says, 'All I want to do is act, but nobody takes me seriously.' Well, I knew that someone in her position can't just go out and say, 'Give me a job.' "

"I mean, I dated Bob Evans, I've known him all my life," she says. "How do I call up the head of Paramount and say, 'How about work?' "

"So I said," says Rivers. "I have an idea."

Howard Hughes died in 1976, and Moore's former manager, who had become a television anchorman, revealed on his show that Moore had married Hughes on a yacht in 1949. The ceremony was conducted by the ship's captain and recorded in the log, which Hughes later destroyed in the presence of witnesses. (They later signed affidavits on Moore's behalf.) The marriage was kept secret, as was their break-up--they never officially divorced--two years later, and their subsequent reconciliation after a few months, which lasted off and on, she says, until 1956. The reason for the secrecy, she says, was that it would have ruined her career.

"At that time the studio ruled your life. I was under contract to Columbia . . . At this time I had not done a sexy role. I was still the girl with the animals: the girl with the gorilla in 'Mighty Joe Young,' the girl with 'Son of Lassie,' the girl with the horse in 'Return of October,' and Rupert the squirrel in 'The Great Rupert.' It would have killed my career, not just to have a divorce but to be married to a man who was 43 years old."

At that time her career was indeed very promising. She got an Academy Award nomination in 1952 for "Come Back Little Sheba." Later she had a featured role in "Daddy Long Legs" (1955), was in Pat Boone's first movie, "Bernadine," and was the bad girl, Betty Anderson, in "Peyton Place." There was a host of lesser-known pictures as well, from "Beneath the 12-Mile Reef" (Robert Wagner fights an octopus) to "Platinum High School" (Mickey Rooney was her father) and "Shack Out on 101."

Columbia, where she was under contract for several years, promoted a romance between her and a football player, Glen Davis, around the time she found Hughes with another woman and walked out in 1951. "The night before I married him Davis I kept saying, 'No, no, I can't do it,' but I couldn't tell anybody why . . . Right up to the last minute I knew that Howard would never let me do it, that he would stop it. And then it happened, and I was frightened."

In short, she says, she was a bigamist. Not once, but thrice. Her marriage to Davis ended after three months. After she and Hughes broke up again in 1956 she married a Panamanian businessman named Eugene McGrath, "because he was as powerful in Central and South America as Howard was in the U.S.," and lived for three years in Venezuela. They divorced, and she married Cramer in 1959, when she was 30, and gave up her career to bear children.

She was never after Hughes' money, she says. She just wanted the marriage acknowledged. She was tired of everyone saying how wonderful Jean Peters was not to be making a claim, when, as a result of the Moore-Hughes marriage never having been dissolved, "they were never really married." Furthermore, "Howard always said she was like a best friend. She was just a buddy. They never even lived together even after they married . . . the truth is, she couldn't say anything because if she did her money stopped."

"Hold it, that's in the book, so save that," Rivers cautions.

"So I just got tired of everybody thinking that I wasn't what they thought somebody else was, when I had been his wife. And still am," she says.

She really didn't want the money? Two and a half billion dollars?

"No way. I think I'm happier now than I've ever been in my life. I have seen what's happened to Howard, to Nicky Hilton--who also wanted to marry me--to Elvis, I mean I've seen that too much money is as bad as not enough."

"Let me ask you a question," says Rivers. "If you had $5 million, $50 million or $500 million, you think you would be different? Let me tell you something. All you need is a million and a half dollars. If you have a million and half dollars invested properly, you can live as if you had a billion."

"Too much money brings resentment, brings responsibility," says Moore. "You get a tiger by the tail and you can't let go."

"After awhile you can't spend more than what you can enjoy," says Rivers.

"I believe in high thinking and simple living," says Moore.

And anyway, Rivers adds, "just because she didn't get two and a half billion doesn't mean she got chopped liver."

In any case, her career renewal program was well under way before the added "bonus" of the Hughes settlement came along. Rivers' idea was that she write about her life with Howard Hughes.

"I said, 'Forget the litigation, because it will be 500 moons before it's settled, just write the story.' She has a story that no one else has. I said, 'We will hire the best agent in the world, Swifty Lazar, and just the noise that you have the definitive book on what Howard was like, that should give you enough publicity that people will say, "Hey, she's for real, and take a look at her! She's 50 and she's gorgeous." ' My scheme was: 'Write the book, ask for an astronomical advance--something you know you can't get. Ask for $5 million up front for this book. You know you won't get it, but the fact you're asking $5 million will make noise . . . Then we'll have you on the talk shows and all that, some producer will see you and offer you a movie or a TV show.' "

Now, he says, Lazar is juggling offers from "four major publishing companies." (Lazar says there have been no "firm offers" for the book, but that several firms are interested.) There are seven other offers for the movie rights even before the book has been finished, Rivers says. As a bonus, he adds, 16 minutes of taped telephone conversation between Moore and Hughes will be released with the book.

There is, of course, a story behind the tapes, too. At one point during her relationship with Hughes, Moore says, someone was trying to blackmail her, and Hughes gave her a tape recorder to record telephone calls. In the process she recorded "hours" of conversation between Hughes and herself, most of which she erased later while taping singing lessons. Nonetheless, some 45 minutes of talk remained, and, she says, "you can tell it's married people talking."

Then, a few days after the news about the settlement broke, Zsa Zsa Gabor was fired from "Forty Carats" in Philadelphia after--according to the theater management--she asked that a group of wheelchair-bound patrons from a center for the handicapped be moved from the first rows of the theater because they were bothering her. Gabor has denied the claim.

Moore was asked by Mickey Rooney, a part-owner of the theater, to take over the role with barely three days of rehearsal. She had never even heard of the play, and had to carry a script the first night. She hadn't been on a stage since 1976, when she appeared in Las Vegas in a comedy called "Who Gets the Drapes." Her previous stage experience was largely during the 1950s, when she performed in summer stock during breaks between movies.

"I was against it," Rivers says. "I said she'll get labeled dinner theater, and the money is not that great. We were supposed to go on vacation. But Terry and her agent outvoted me . . . She said she didn't mind doing dinner theater, she just wanted to get back in front of an audience. I called Lazar, and he said do it! Get her name back in the paper, it will be great. Apparently the pros were right."

Now, he says, Moore's agent has received 21 offers of work for her. There are two movies and a television series (which she wrote with a friend) in the offing, and the book and the movie . . .

The handicapped people came back to see "Forty Carats" on Moore's third night and she had a party for them backstage after the show.

Her performance shows the lack of rehearsal, but with the help of the other cast members she gets through the frothy comedy about a 40-year-old woman who falls in love with a 22-year-old man. Due to the short notice, she provided her 14 costumes from her own wardrobe, and flew in her mother to help her manage them all. Unfortunately, the last part of the play takes place in New York in December, but no one seems to notice that she is the only one wearing silk sundresses while the others are prepared for winter chill.

"Mickey called me because he knows I'm the kind of actress who really takes things serious," she says. "He believes in my talent. Elia Kazan who directed her in "Man on a Tightrope" in 1953 said I was one of the best actresses of my age. He's given me a letter. So has drama coach Stella Adler. I don't know of any other actresses who have letters from those two people, and I didn't ask for them."

"I firmly predict," says Rivers, "that Terry is going to be The Celebrity of 1984."

But the celebrity is not just for personal gain. Four years ago Moore cofounded a charity for victims of spinal and brain injuries called "Help them Walk Again." It has built a free clinic in Las Vegas, and Moore has even adopted--through the Mormon church, of which she is a member--a brain-damaged American Indian boy who cannot move or speak.

She wants to raise money to build a swimming pool. "But people don't listen to you unless you have celebrity," she says. "How can Terry Moore help them walk again unless Terry Moore is famous and can raise some money?"

Indeed, some of the money she got from the Hughes estate will be given to the clinic. "I was going to fight and see that his money went to medicine. Howard and I believed in it so much . . . We always said that happiness was being able to run. All your faculties have to be working."

She doesn't believe the stories about Hughes' last days as an emaciated recluse, and thinks that he was victimized and manipulated by greedy aides. The man she knew was exciting, powerful, "the greatest lover I've ever known. Howard was everything to me, he was my world."

"I liked him very much," says Moore's mother, Luella Koford. "They seemed to enjoy the same things, bowling and things like that. Of course, he was always flying around . . . When they had a quarrel he'd come and tell me his side of it first."

"He used to put his head in Mama's lap--"says Moore.

"And cry!" Koford adds.

"He'd say, 'I'm an orphan! Helen Moore's given name has you and Papa, and I'm an orphan.' He really did make you feel sorry for him," Moore says.

"I did feel sorry for him," her mother says, "because Terry gave him a rough time sometimes. He had that quality about him, he got your sympathy."

The last time Moore spoke to Hughes he was about 60, but she won't say what they talked about.

"Got to save something for the book."