I get a catalog from "Micro-Mark" the small tool specialist". www.micromark.com 1-800-225-1066.

They have some useful things, including a bunch of small clamps, fasteners, drills, Dremel & accessories ++++++++++++++++++++++ Some items specifically for Modelers.

Small Parts & Reid tool are possibly 2 more sources for some items. I have catalogs from both.

Wholesale tool, Enco, and other industrial suppliers offer fasteners (screws) and more. One of these offers screws in lots of 25 at a good price. Enco I think.

I have so many catalogs it is hard to keep up.

Some computer & other electronic catalogs have parts for servicing E-gear that might help.