Hence the mission of the Olympia Theater at Gusman Center's 75th Anniversary Weekend: to raise funds for its restoration. On the agenda Friday is a vaudeville performance and party featuring flappers and refreshments, of the alcoholic kind we suppose. Saturday boasts a return to the glory days of the movie palace with a marathon of budget-priced classic flicks such as National Velvet, The Wizard of Oz, Viva Las Vegas, North by Northwest, Casablanca, and King Kong. Now, that's entertainment!