Sometimes he signed "George Washington alias Jan Leighton," sometimes the other way around. But even under his Continental Army braid, TV fans among Daughters of the American Revolution recognized the New York actor as the charmin' Mr. Whipple II and any number of the 1,900 other roles he's played in his career.

Several hundred DARs squeezed into the DAR Museum yesterday to find Leighton the only contemporary aspect of an exhibition titled "The World Turned Upside Down," commemorating the 200th anniversary of the victory at Yorktown. All around him were portraits and drawings of American and French Revolutionary War heroes, the most numerous those of George Washington.

Gilbert Stuart's work, on loan from the Corcoran, was easily the most familiar -- or, as someone once wrote: "If Washington were to rise from the grave and not resemble Stuart's portrait, he would be rejected as an imposter."

With Antoinette de Laboulaye representing her husband, French Ambassador Francois de Laboulaye, the exhibit was opened yesterday by DAR president-general Patricia Shelby. "We owe the people of France a great deal of gratitude," she said. "Without a victory at Yorktown, we very well may not have been here today to enjoy the freedoms we do."

Last night, continuing its observance of the end of the War for Independence, DARs gathered at Constitution Hall for a gala evening, with actor Leighton portraying George Washington in a salute to the patriots. Among guests were the ambassadors of France, Canada, the United Kingdom, Spain, the Netherlands and West Germany.