so my grandfather has a Kahr K9 that he recently got back from someone he sold it to, and it was returned in less than optimum condition. Seeing as he likes to keep them immaculate, having several small scratches on the finish of a firearm drives him crazy. What do y’all use to maintain or restore the finish on a black or blued firearm? There aren’t any major scratches that go straight to the metal, and I’ve been told that car wax should do the trick of making it look like new again. Thoughts?