It's pretty rare to find vintage stuff in a shop here. Red Lantern on Myrtle Avenue here in Brooklyn sells used vintage bikes, and they sometimes have some bits and bobs lying around. Very nice guys over there. They also have a bar / coffee shop in the bike shop. Pretty cool.

Bespoke on Lafayette, also in Brooklyn, sells VO and modern classic type-stuff. Those are the two shops I frequent when I need something.