Guys I currently work as a tool repair technician for a large aerospace company, and they get rid of old serviceable tools of all kinds, with regular employee tool sales and giveaways. Because of this I get great deals on all kinds of stuff, from pneumatic drills (of all types and sizes), air ratchets, 90 degree die grinders, pneumatic screw guns, dial calipers, ball gauges, radius gages, feeler gauges, clamps, hole saws, pancake drills, manual and pneumatic rivet squeezes, cleco clamps, carbide burrs, step drills, etc..... A lot of the tooling I get is useable in the AK building, or general gunsmithing, world.
If there is anything that you're looking for in specific, shoot me a PM and I'll see if I have it. (or email me at: Jetmd928@gmail.com) Depending on what it is, and how many I have, prices could run anywhere from free (well, just cover the shipping cost) for small simple stuff, up to about $400.00 for a pneumatic rivet squeeze. Always interested in parts and supplies trades as well.