Hi Rich, I'm not sure but I would suspect mostly Lugers. Sometimes just the cleaning up of a part or two will improve looks quite a bit, other times the whole gun needs some loving? I agree on the acid strip / dip blue idea. It takes forever in my world, to sand and polish parts, large or small. I would have to experiment a little. I would have an outside source do the bluing... I can do the niter blue and straw... To make it work I'd have to be able to offer some type of quantity to make it worth while overall, for anyone... That's why i was posting the thought, just to get some feedback on feasibility?... Best to you Rich, til....lat'r....GT....