I recently purchased a used Citori xs sporting. The gun is in near new condition, with a couple of exceptions. When I assembled the gun, I noticed the flat part of the barrel lumps that are flush with the bottom of the frame have a few slight scratches and bruises (nothing on the frame itself though). I was wondering about the best way to touch these up, as they appear to be in the white and appear to be a ground or sanded finish. Any suggestions, as I do not want to change their profile or round the edges or corners of these lumps. Thanks!