Not every clotheshorse is lucky enough to inherit a passel of 1970s Pucci dresses and “Mad Men”-era alligator handbags from a chic grandma. But Oct. 5, Chevy Chase-based Sloans & Kenyon’s Vintage Fashion, Couture and Jewelry auction lets all bidders in on a shot to score evening gowns, jewelry and shoes from past decades, plus a smattering of current-day couture. “We’ve got such great consignors, and their clothes really have stories,” says Lisa Jones, the auction house’s Director of Silver and Decorative Arts Costumes, Textiles and Fashion. “They’ll tell me, ‘I wore this dress to a White House party or that suit when People profiled me.’ ” Highlights under the hammer: a 1980s dress that resembles a Mondrian painting and several 1920s Chanel necklaces that once belonged to a prima ballerina. Bid in person Oct. 4, starting at 11 a.m., or submit an absentee, internet or phone bid. Previews of the merchandise take place Oct. 2-4.