www.penncamera.com - they have 5-6 stores throughout DC, Northern VA, and Maryland.
It's probably even better to CALL them (I'm guessing you live in the states - the whole B&H and Adorama reference and all...). You may be looking for something they may not have listed - if they deal with the company (Canon, Schneider, Leica, Nikon, Hasselblad, etc.) they can get whatever that company makes (obscure parts, accessories, etc.).

Hope that helps - good luck!
-Lew ;-)