A great place to look is Simpson Ltd. Every couple of months they get in a few dozen German guns that are usually OK mechanically but for some reason or other the stocks are generally cracked and repaired and some need rebluing. For $350 I picked up a 1950's JP Sauer 12ga ejector that only had some rust on the exterior of one of the barrels. Took it apart, cleaned it up and spent a few hours with Kroil and a copper pick to remove the rust.
Most of them have stock problems though. Tuesday someone got a decent AYA sidelock 12ga for $350. It's hit or miss.
