I know I can't use them as rear brakes, but the front maybe? Bought them at a swap meet, and they have Audi markings on them?

You'll have to confirm:

1. Mounting bolt spacing.
2. Make sure the rotor is centered in between the pads.
3. Make sure the caliper will fit the rotor overall diameter.

Those look like VW Bus or Vanagon calipers .......................... The Cap'n

I was thinking the same thing as the Cap'n. I am going to check my bus.

Just looked. Those should be from a late bay window bus or vanagon with 3.5" bolt spacing.

Looks like they are getting sold...