The current plan is to use the same stuff I use to polish plastics in the shop...starts finer than anything most people have and ends looking like fabric, but leaves a mirror finish when you're done. I was going to either put the polishing cloths on my granite flat plate or use something suitably hard to back them up. Should be able to leave a mirror finish without removing more than the material above the median scratch. I want to attack some Austrian trigger parts that look like they were stamped by Donald Duck as well; I hear putting a polish on the mating surfaces can remove some of that Teutonic grittiness in the action.

Given the possibility this has been used in a 22 upper, and even though I would flush it all out very carefully after each use if that were the case, there is also the potential for ground glass from the primer mucking up the works. It might be worth using this elsewhere and putting a single stage in anything that gets regularly sand-blasted.

Thanks for the heads-up on the Dremel; I wouldn't use one for something like this; not enough control on small parts, but it's always good to bring it up!