Ok, I get you now. I have experienced similar problems with some of my Great War figs - particularly beneath the brims of helmets, and beneath packs. Almost looks like some sort of metal tumor. Have been able to get rid of a lot of this, with some work, but other pieces are very difficult.
No need for a photo. Totally understand what you're talking about now. Good to know it's not a problem on the majority of figs, in your experience, though.
-Doc