A bore and choke gauge will tell you a lot re excessive honing. If we're talking European guns and it's far enough out of spec to be out of proof, that's a red flag--unless it carries the proper reproof marks at the current bore diameter. Fairly easy to carry a bore and choke gauge with you as you walk around a gun show. Wall thickness gauge is a bit more problematic. But if the bore diameter throws up that red flag, you can always go retrieve the wall thickness gauge from your vehicle if you're still interested enough to check.
