Gunnut has some good suggestions here. For my own 2 cents, one thing that works well on those epoxy finished stocks is to level out the scratches with sandpaper, then use fine glass beads over the whole thing at pretty low pressure, maybe 35 pounds or so. It leaves a nice satin finish that is quite pleasing and not as gaudy. For the metal, I have been playing with KG Industries Gun Kote recently. It comes in lots of colors, goes on with an airbrush, and after you bake it at 350 deg. F for an hour it's some kind of tough. Brownells sells it too, repackaged in their own cans but it's cheaper if you go to the source, and you can get some pretty wild colors if you want.