Cleaning up a 1920 commercial

[Lugerdoc]

Dr.Herb, It's possible that a metal polish and dremil polishing will remove "the crud", but this patina, is actually microscopic pitting, so since it is only on the surface, it can be polished off. If you don't want to deform the contours of these parts, I suggest that you have Thor do it for you, as this is his area of expertise. Tom