The old Melrose Diner sits in weed-infested disarray just outside Trenton, N.J., at the intersection of Route 130 and Meadowbrook. Across Meadowbrook, an asphalt crew is re-covering the National Pools and Spas parking lot. Across 130, the Ideal Auto Sales lot has given up the ghost.

The diner's horizontal bands of orange and cream enamel have faded and lost their youthful enthusiasm. Its doors boarded up to keep local youths out, its external lighting fixtures ripped from the sockets, the diner is swathed in vines that creep through the sidewalk, snake past broken glass. The clock that once greeted customers is gone, and the dead neon no longer reads "MELROSE" as it first did, or "IRENE'S WINDSOR DINER" as it did later on. Now, it's just "DINER." Generic.

But next month, if all goes as planned, this particular diner will be saying goodbye to National Pools and Spas and the Ideal Auto Sales lot. Perched on wheels, it will ride down to Washington, there to take up residence in the Smithsonian National Museum of American History, the first diner on the Mall.

For now, only one-quarter of the 1940 eatery will grace the museum, installed as part of a permanent exhibit called "The Material World" scheduled to open next April. The other three-quarters of the former Melrose Diner, fully studied and documented by Smithsonian staff, will wait in storage; "Material World" exhibit coordinator Claudine Klose hopes it will eventually be reassembled and go on display.

"The best way oftalking about the new materials of the '30s and '40s is with a diner and a jukebox," says Klose.

She has already persuaded a Virginia collector to lend a 1946 jukebox. The first to be made with acrylics, it is known as "The Mother of Plastic." (Really.)

And now she has her diner.

The Old Melrose When Richard Kubach designed his new diner, he knew exactly what he wanted: Everything would be the newest, the shiniest, the best.

"I have the most modern equipment that I could possibly afford," he told The Diner magazine in 1940. "I have a potato peeler, a silver burnisher, a dishwasher, up to the minute ranges and ovens, de luxe refrigeration, and the best hot water system. That is not enough. These things, I know will pay for themselves, but they don't impress the customer because he doesn't know I have them. So for him I have air conditioning and the new Sterilseat Toilet cover. These things he knows react to his comfort and safety."

"I more or less demanded all the details," the 79-year-old Kubach says now. "I personally designed it. I taught the manufacturer how to build it."

To fit 25 stools and eight booths, he added extensions of glass brick, a touch diner scholar Richard Gutman calls unique. "With the way architects are now using glass bricks," Gutman says, "they would look at those additions and say, 'WOW!' "

The Search When the people at the Smithsonian started looking for a diner, they weren't quite sure what they wanted. They did know their dream diner, wherever it was, would be from the era Gutman calls "the golden age of the diner": 1933 to 1947. It would have the original stainless steel, vinyl and Formica, materials considered the highest of tech in the '40s. And it would be owned by someone willing to accept merely glory and a tax credit return for a donation, for the Smithsonian didn't want to pay.

Exhibit designer Jeff E. Howard was going on vacation in New York and offered to take his diner books along and search out promising candidates. New Jersey and New York were the homes not only of most of the nation's diner manufacturers, but also many archetypal diners, with their streamlined exteriors and light-suffused glass bricks, their leatherette booths and pink and blue and green and white neon signs. "Open," they called out. "Ted's Diner." "Home of Fine Food." "Tick Tock Diner." "Air Conditioned." "Blissville Diner."

Outside Trenton, Howard found the Smithsonian's dream, complete with a for-sale sign: The classic diner that had been built for Kubach, whose son Richard Jr. now manages the current Melrose Diner in Philadelphia. Kubach sold the old Melrose in 1956 when he built the new Melrose, and it was carted off to New Jersey, there to fail and lie fallow for years. Finally, Trenton businessman Camillo Petito, owner of a fast-food restaurant that gives the Chicken Holiday Plaza its name, bought the land the old Melrose sits on and was only too happy to agree when the Smithsonian offered to rid him of his stainless steel and Formica burden.

"I thought the diner they were considering was really the perfect one," says Gutman, coauthor of the 1979 "American Diner." "It hasn't been represented in other museums or exhibitions -- that period, that style. And another reason that this is a good diner is that it has gone through these various changes, and it had several lives and it's still there and the family that ran it originally is still running diners."

The old Melrose diner was built 56 years after Samuel Messer Jones created the first lunch wagon a customer could enter -- the precursor of the diner. Soon, companies were manufacturing lunch wagons and shipping them off to enterprising souls up and down the East Coast, giving the diner its basic definition. In Gutman's words, "A diner has always been and continues to be a prefabricated restaurant with counter service, built in sections in a factory and transported to a distant site."

Over the years, diners have had their ups and downs. From the beginning, the establishments were open during the night and attracted a crowd politely described by some as "rough." Before the mid-'20s, women usually avoided diners, but then diner owners began to court them as customers, adding booths since stools were considered both uncomfortable and somehow unladylike. The transformation of decrepit trolley cars into diners around the turn of the century hadn't helped, and it wasn't until easy-to-clean materials like stainless steel and Formica and tile were introduced (along with new names like "White Manna Hamburgers," chosen by clever owners to suggest the places were spotless) that the diner began to shed its shoddy image.

By the late '30s, the diner had passed through its awkward years.

The New Melrose When Richard Kubach Sr. talks about that old diner now languishing in New Jersey, his voice has a slightly defensive tone, as if he will be held responsible for the sad state of his one-time business. He is the teacher who did his best by a student, only to see him leave school and take up a life of crime. "I was sorry to know that diner failed, but it was not managed well," he says. "The building is not the thing -- it's the employes and the manager."

Kubach makes no pretenses to being a historian. He is a businessman, and to him an ancient failed diner is an ancient failed diner, not an artifact.

Kubach got into the diner business in 1930 as a dishwasher after the factory where he was working closed. A year later he was manager, and four years after that he bought his first diner -- the used, 19-stool Superior Diner wedged into the crowded streets of small homes in South Philadelphia, one block away from the site of the diner his son now runs. Since the place had a bad reputation, Kubach decided to get rid of the Superior and its ironic associations, and because he thought no one could spell or pronounce his name ("You know Johann Sebastian Bach? It's Ku-bach like that"), he felt he couldn't go the obvious route. A practical man, he looked down at the can of Melrose Tomatoes in his hand. His diner had a name.

Within five years, the Melrose boasted the fastest turnover per stool of any diner in Philadelphia, and Kubach was ready for what he called "the new modern Melrose Diner" -- the paradigmatic diner that will soon go to the Smithsonian.

Kubach sits now in the office behind the even newer Melrose, a 107-seat neighborhood institution of stainless steel, neon and Formica Kubach designed in 1956 with as much care as he lavished on its predecessor. The new Melrose booths alone went through seven miniature and seven full-scale models before Kubach found the perfect shape -- an amoebalike U with a small center divider so two parties can sit in the same booth. Under the table, there is another divider "so when it's two parties," says Richard Jr., "no one can play footsie with someone else's wife."

The present Melrose Diner is everything you would expect it to be, from the clock outside in the shape of a coffee cup (complete with fork and knife serving as hands) to the orange naugahyde cushions on the counter seats to the waitresses wearing shirts of black and white and expressions of put-upon pragmatism.

The man behind the Melrose Diner became a Philadelphia restaurant institution himself, once serving as president of the Philadelphia Restaurant Association and still happy to proffer opinions on such subjects as the introduction of soft drinks into the diner menu in the late '30s, which he saw as "a definitely harmful tendency."

"I have found through experience that the customer starts laying off the hot platters and takes the sandwich and the soda whenever it is possible to get a soda," he told The Diner magazine. "Other men have told me that serving soft drinks has cut their average check in half."

But now, many years and soft drinks later, it is lunch time. Out front, patrons are being served within the promised five minutes and Angelo Koskinas ("The best sandwich man we've ever had," says Kubach Sr. about Koskinas, who's been at the diner for 32 years) is producing his 31st club sandwich of the day. Back in the office, under the framed, full-color photograph of a Melrose Diner cheesecake, Kubachs Sr. and Jr. and their general manager Paul Tierney, who also has been at the diner for 32 years, are inspecting a new sort of steak they may soon offer to the 3,000 people who eat at the Melrose in every 24-hour-long day.

"There are few days when we eat, per se," says Kubach Jr. "We're always testing."

Like many others, Kubach Sr. was drawn to diners for one basic reason: With a relatively small outlay of money ($18,000 for the 1949 Melrose), any man could own one. In 1940, The Diner decreed Kubach "the one thoroughly happy Dining Car owner we have ever met." Perhaps that was because when he discovered diners, he discovered his calling.

"I'm enthusiastic about the dining car business," Kubach says even now. "When you look at a diner, you're expecting a kind of service, price level -- you know you have counter service, too, which some people want and some people don't want. When we moved here, there was an old police station with a beautiful basement. We said, 'This would make a beautiful restaurant,' but I was of the belief that there is nothing like a diner, in the long run, that would have the attraction, that would say what kind of service you had, and the cost of it. With a restaurant, from the outside, I don't know what it is. You don't know if you can buy a cup of coffee or afford dinner.

"One thing I felt was that the diner was the only American-type restaurant existing in the world at that time. For that reason, we only serve American food. We are in an Italian neighborhood, but we never served spaghetti. It was an American idea. I didn't see any diners in Germany where I come from or anywhere else, and I had traveled all over the world. I also wanted it to be American in its operation."

Kubach says that from the age of 14, he planned to go into business for himself. As a teen-ager in Stuttgart ("I was manufactured in the same city as the Mercedes, but they didn't make me as perfect"), he read a book by Henry Ford and was converted.

"I wanted to run my business like Henry Ford ran his business. I wanted my employes to have as good conditions as they possibly could. By having satisfied employes you will have more satisfied customers."

Many of the employes have worked at the diner for decades, some following their parents into Melrose jobs. Kubach estimates that 98 percent of the customers are repeat visitors. Over the years, the Melrose has become something of a local legend. As the Kubach father-and-son team gives yet another journalist the extensive diner tour (kitchen, bakery, cake decorating room, storage room, elevator, basement, freezer room, garbage room, another storage room, conference room) a regular calls out "More free publicity!" Local and national politicians make campaign appearances at the Melrose, and the diner is celebrated in newspapers and on TV so regularly the 130 employes have developed well-practiced interview responses.

One waitress, for example, laughs when asked if she ever thinks of leaving. "I'm just not sure yet if the job is steady!"

Look at the coffee-cup pin (copied from the coffee-cup clock outside) and you learn not only her name, but the year of her arrival at the diner. Jean DiElsi. 1943.

The Food Club sandwiches. Fried eggs. Late-night cups of coffee. Plates laden with french fries. Hot turkey sandwiches. In back, trays hold decorated cakes wishing Sharon a happy birthday, Ken good luck, Veronica showers of happiness. Each year the Melrose sells $250,000 worth of those cakes.

Kubach Jr.: "We are sensitive to our customers' eating patterns. The menu has probably contracted over 30 years. We've gotten into a more standardized menu by tracking what the customers like. We used to have a lot of very affordable meals, if I can put it that way. People don't want them as much when they become affluent."

Kubach Sr.: "The meat loaf, the chicken croquettes."

Kubach Jr.: "Sweetbreads. Kidneys. Back then, nobody ate those if they didn't have to. Now, they've started showing up in gourmet restaurants."

Richard Kubach Jr. smiles. The diner business is not without its ironies.

The Future While Richard Kubach Sr. talks of air conditioning and apple pies, his son speaks of "modifications to our system" and the "cell structure damage" blueberries suffer when frozen incorrectly.

"I finally made it a goal to go into the business when I was 12," says Kubach Jr., who admits that some of the older employes still call him "little Rich." Although he started learning how to cook at 6, little Rich subsequently grew up and for a time his interests turned away from chicken croquettes and chocolate cream pies and toward computers and electrical engineering. "Even though I set my sights in sixth grade," he says, "my road wasn't always straight." But after hotel management school at Cornell and four years in business, he came home.

While diner manufacturers catered to the public's increasing taste for those antihistorical creatures -- the neocolonial diners and the mansard-roof diners and all the other diners that bore little resemblance to the real thing -- the Kubachs kept the Melrose constant, resisting redesign and the general wave of diner pessimism.

"We went through a period when they were predicting the diner was going to become a thing of the past," says Kubach Jr. "In the mid-to-late '70s, they were beginning to write newspaper articles about that, but you don't see that anymore. Some of it has to do with nostalgia -- it's a connection with the '50s. It's a desire, maybe, to get back to a full menu, the quality and the service."

Diner design has always followed popular taste rather than led it, and "nowadays, people are rather interested in preservation in commonplace things," says Gutman. The diner is, again, following. The Modern Diner in Pawtucket, R.I., for example, is now included on the National Register of Historic Places, and trend-attuned entrepreneurs have opened nouvelle diners -- slick, kitschy, overpriced places, most of which feel as much like real diners as apartments decorated in trendy neo-'50s furniture feel like Beaver Cleaver's living room.

Philadelphia architect and diner aficionado David Slovic is currently working with an Atlanta businessman to renovate an old diner into a new restaurant. "It has something to do with authenticity, I think," he says of the burgeoning enthusiasm for diners. "It's not a fern bar place that's filled with all kinds of nostalgic tsatskes. That whole Victoriana theme, I think, has gone as far as it's going to go.

"The reason I like the diner and the reason I did so much looking was that I think it touched something special in the American culture. It caught some sort of quality about America that we all liked and could all agree upon. I think it's that sense people want to capture again in a new diner."

Gutman sees the new diners more as projections of a vague nostalgia than accurate re-creations of an American original.

"I think to a certain extent they're following the fascination with postmodernism," he says. "Especially the new diner-concept-things people are building that are not done by the diner manufacturers -- those are really people's fantasies of the ideal place. They're just images from people's thoughts of the past."

This too, of course, shall pass. The diner-lovers-come-lately will find another object on which to fixate, and people like Gutman and Slovic and the Kubach family will once again be on their own. Except then, they'll have the Melrose on the Mall.