O Mistress Mine is the A(c)minence grise of West Village vintage, in business for 33 years. In all that time, the owner has learned a thing or two: For one thing, there is incense burning to cover up that vintage aroma. The day we visit, a feeling of camaraderie has developed among shoppers: When a woman hesitates about trying on a ruffly blue two-piece number, she's convinced by the fact that everything in the shop is now 20 percent off, making the outfit $48 instead of $60. This also makes the saucy cocktail aprons $12 instead of $15; a gray cardigan, heavy with sequined flowers, is now $66 rather than $80. Just as we are deciding whether to try on an exquisite black eyelet dressait's $110, but then again that's before the 20 percent offaNPR, which has been playing softly in the background (we are, after all, in the Village) begins a documentary about Bellevue. The announcer is cheerfully intoning, "On the ward this day there's a man with neuro-syphilis," but curiously enough, this doesn't kill the mood. We continue to try on the lightly frayed suede car coats and old prom dresses just as people have been doing here for more than three decades.