IN PREVIEW. Classic American preppy meets urban for durable downtown looks. Anti-flash threads from Atelier Production et Création (A.P.C.) are fully credible, from mainstream Paris and back across the pond to NYC. Emphasis on oxfords and unwashed denim for men; cute, simply cut tent dresses for women. Just out of price range for the creative underclasses, but still finds a way into many a young thing’s closet.