I have a 2009 manufacturered G23c. I bought it very slightly used a month ago. The slide and frame showed no wear. The slide stop lever and extractor showed some wear (lighter in black color). The extractor had quite a bit of silver showing through on the round in the chamber indicator area. I figured it was a police gun that was holstered putting wear on the lever and indicator. The original copper grease was still in the slide grooves. I ignored the slide stop lever's finish but colored the extractor's chamber indictor area with an industrial black Sharpie. After a couple of range sessions, the black color on the chamber indicator had worn off again. None of my other Glocks have ever shown any noticeable finish wear on the extractor. Is this normal? Not a big functional deal, but any advice about refinishing it permanently? The gun has run 100% since I bought it. The rest of the gun looks new.