Unlike its sister store, Laurel Canyon, which celebrates ’70s bohemia, Chelsea Girl carries only high-end vintage, including YSL, Diane Von Furstenberg and the wild pastels of Pucci. For the pending collegiate or whimsical weekender, it’s stocked up on prom dresses from the ’50s (slip on wasp-waisted silks and organzas by Ceil Chapman) and the ’80s (do the rock-glam thing with Victor Costa’s edgy ruffles).