You might try a touch-up pen made for guns. Birchwood makes some that can be purchased at Amazon, Midway, and Brownells. I installed a set of Meps night sights on my Tristar C-100. Because I don't have all the proper tools and am not a smith, there were a few light marks on the finish. I did not have metal showing through, but am happy with the results of the touch-up. I think I got a flat finish pen from Midway. Anyway, it won't set you back too much to try it.