It was early in the evening when Buzz Potter drove up in front of the Ebbitt Grill in his 1928 Lincoln - a pale green splendor, roof down, black fenders shiny. He used his handkerchief glass, and lent himself and his car to preserving history.

"No one dares to tow it away, even though he's illegally parked," said a steady worker at the Ebbitt.

The folks at the Old Ebbitt Grill figured that a little bash of their own might keep the wrecker's ball away, so yesterday afternoon they invited o and all to join them in "a bit of cheer" at the famous saloon on F Street near the Treasury Department.

The party flowed onto the street and the Old Ebbitt Grill never had it so good -- a jazz band, tables moved onto the sidewalk, balloons decorating and old cafe, bringing it alive.

All the worry has to do with the plans of Oliver Carr and associates to knock down the buildings on the block to develop a shopping mall.

"This is the noblest job we've ever played," declared Alan Webber, selfproclaimed "Commissioner of Trombone" in the Federal Jazz Commission, which tried to minimize the blues during a series of short sets inside and outside the Ebbitt.

"To save a saloon is something I've wanted to do all my life," added Webber, taking a break to keep his lips lubricated.

Nearby, Stuart Davidson, the president of Clydes, Inc., looked wistfully at the Grill's antique interior: "I can't duplicate it. I can't get high ceilings like that," Clyde's picked up the Old Ebbitt for $11,200 in 1970 at a federal auction. They've spent $130,000 since then to rebuild it.

James Symington, the former representative from Missouri who now practices law in Washington, acted as the cohost with Davidson for the rally. He explained that the future of the Grill rested with three centers of power: the Interior Department, the City Council and the Congress. A bill has been offered by Rep. Morris Udall to expand the boundaries of the Pennsylvania Avenue national historic site to include the Grill, but Symington suggested that the bill might not be necessary.

"We thing Secretary [Cecil] Andrus already has the power this bill would confer on him. We think he thinks so, too, but he's disclined to do something until he's sure there are funds available to back it up."

Those funds probably would have to come from the District Appropriations Committee. Several revelers mentioned that the chairman of that committe, Rep. Charles Wilson, visits the Grill reularly.

"He didn't even know that it was threatened until we told him what was going on," said one woman with a look of great relief that the information had now been passed along.

For Eugene Sarnoff, the festivites were well-deserved by the "new" watering-hole on the block.

Sarnoff started out sweeping floors at Copenhaver Stationers in the building in 1912, when the original Ebbitt Grill was back at 14th and F Streets. He ended up president of the company.

"This building has always had a place in my heart. It was the start of my career" he said.

Standing a little way down F Street, Lula McGowan and several of her family from Jackson, Miss., watched the party until they were asked to join in.

The jazz band, playing nice and lud, started the evening with the hymn "Just a Little While to Stay Here" and the mood prevailed roughout the evening. CAPTION: Picture, James Symington, center, talks with Stuart Davidson as members of the Federal Jazz Commission perform; By Joe Heiberger - The Washington Post