This place is incredible. I've been searching for replacement shower door rollers (not your Home Depot variety) for months with no success. Just today I was referred to Barry Supply Company. I was doubtful given my repeated failures, but walked over just to check the place out.
The shop is located inside a dingy hole-in-the-wall on 17th Street. Stepping inside, you are greeted by the shopkeeper through a metal grate. I described my hardware to him, almost apologetically, sure he would not have it.
Within a few seconds of rummaging, he had an exact match for me! It made my day! Be prepared to pay a premium, as many of their goods are not manufactured at all anymore. Nonetheless, I highly recommend stopping in if you're on a frustrated hunt for obsolete hardware. Chances are Barry Supply Company will be able to help you.