Angus Olson, a 52-year-old expert in international development, gazed at the small bright-red convertible as if his mind were somewhere else. It was a 1964 1/2 Ford Mustang, polished to an unearthly sheen as the model for a new postage stamp. He had owned a car like it once.

That was in 1965. He had just arrived at Loyola University in New Orleans. He bought his Mustang, a burgundy coupe, for $2,400. He remembers four years of cruising through the French Quarter and parking beside Lake Pontchartrain before he graduated, married and turned in the Mustang for a larger, more practical Oldsmobile.

Yesterday, Olson went to the Merrifield post office in Fairfax County to buy 15 new stamps commemorating the 1960s. As part of the U.S. Postal Service's Celebrate the Century program, post office employees set up booths outside and put other classic cars on display. But the Rangoon red Mustang had the prime spot on the lawn.

It might seem odd to put a cheap American sports car in the same category as the subjects of the other commemorative stamps, such as the landing on the moon, the Rev. Martin Luther King Jr., the integrated circuit and the Vietnam War.

But as a succession of men, and some women, in their forties and fifties stopped by the car to look and dream, the Mustang's social significance became clear. How many proposals were made, how many lives begun in the back seats of the little automobiles?

The car was a commercial sensation--22,000 orders the first day and more than a million sold in less than two years. The crowded schools of the 1970s, the cultural dominance of rock-and-roll and a succession of oil crises can all be traced in part to the Mustang and the romance it inspired in young adults who have gone on to quieter lives as lawyers, teachers, consultants and newspaper publishers.

"It was the hottest car of its time," Olson said.

He moved a hand over the standard black interior and inspected the power convertible top, remote mirror and D-code 289 engine.

The car belongs to David L. Williams, 52, director of the Learning Resource Center at the Alexandria campus of Northern Virginia Community College. He and his brother Chris, 47, owner of B&C Auto Restoration in Boones Mill, Va., spent seven years, $9,000 (not counting the $1,900 David paid for the car in 1982) and uncountable hours of labor bringing back the glistening innocence the car had when it rolled off the assembly line May 7, 1964. When a Washington photo research company asked to take pictures of it for the use of stamp artist Keith Birdsong, Williams quickly agreed.

Williams has traced the car's history with a devotion usually reserved for the lives of saints. It was purchased by Tom Werbe the day it was unloaded at an Indianapolis dealership.

The salesman agreed to keep it hidden in the back of the lot for two weeks, away from hordes of buyers bidding up Mustang prices, so Werbe could surprise his wife, Barbara, with it on her birthday.

The Werbes' son Dan put it to good use while he attended Wabash College. It was sold to Barbara Werbe's cousin Phoebe Skinner for the use of her son Russell when he attended Virginia Tech. The next owner was Ernie Ellis, who drove it from Springfield to his job at the Pentagon each day, until his wife made him sell it because she didn't like the color.

The Williams brothers said they knew when they bought the car that renovation would take time. "It was a nice five-foot car," said Chris Williams, referring to the minimum distance one could stand from it without noticing the rust.

David Williams said that when he drove it into his brother's shop, "he had the [acetylene] torch lit already." Soon the car was in pieces. "It's got to get ugly before it gets pretty," Chris Williams said.

Chris Williams's son Schon, 21, recently graduated from the University of Virginia, where, he reported, automobiles inspire less passion than in his father's day. He had a gray 1987 Mustang, easier to drive and maintain but harder to love than his uncle's bright red bomb.

"Cars these days just aren't as flashy," Schon Williams said.

CAPTION: A poster of a stamp celebrating the Ford Mustang stands next to the real thing. The Mustang was an overnight sensation in the 1960s.