Few things remain unchanged in Los Angeles, and its restaurants are no exception. Long gone are many classic establishments, such as the Brown Derby. Rare indeed are those that live to be 100.

One block north of Union Station, along the outskirts of Chinatown, stands Philippe’s the Original, famous for its French dip sandwich.

To celebrate the centenary of its opening, Philippe’s will be selling its famous dip sandwiches at the 1908 price of 10 cents each, between 4 p.m. and 8 p.m. on Oct. 6.

“Last time we did this was on our 95th anniversary and we were mobbed,” said Richard Binder, who owns and runs the place with brother John.

Anticipating more lines of hungry patrons, the Binder brothers have enlisted the help of Roger Owens, the peanut pitcher of Dodger Stadium fame to entertain the anxious crowd, and the USC marching band. Public television’s Huell Howser is expected to be on hand to record the event for posterity on his “California Gold” show.

“It just goes to show that if you hang around long enough, you become a legend,” said L.A. restaurant critic Merrill Shindler.

Other eateries that have stood the test of time in L.A. are Musso & Frank Grill, dating from 1919; Pacific Dining Car, 1921; and El Cholo, 1923. Cole’s P.E. Buffet, which opened a few months before Philippe the Original, is closed for remodeling.

Philippe’s menu, which offers such delicacies as pickled pigs feet and carved lamb sandwiches, has remained virtually unchanged for nearly 100 years. Famous for the French dip sandwiches, pies and 10 cent coffee, Philippe’s serves about 2,800 people on weekdays and more than 4,000 on weekends, selling about 18,000 beef dips a week and about 10,000 cups of coffee.

Mathieu sold Philippe’s to David and Harry Martin in 1925. The Martins and their in-laws the Binders have run it ever since. Today Philippe’s is open from 6 a.m. to 10 p.m. and serves the whole world of downtown denizens, from laborers to lawyers.