Ouch! That sucks.
OK, so I assume that if you're teaching classes at Georgetown Law, you must be a lawyer. Why can't you just subpoena the tapes, then? Surely there must be some means to acquire them if Security is unwilling to help?
I can't help you with suggestions about second-hand shops, obviously, but I sure do get annoyed when I see those places. Legalized fencing, apparently. The cops here in Portland just look the other way.
Sorry about your Campy wheel.