Any suggestions on removing the tarnish on a revolver? My wife got her late dad's service revolver from when he was an auxillary Cary officer in the '50s-'60s. It probably has not been out of the leather holster for at least 50 years. The leather has started disintergrating and the section of the frame that was in the holster has tarnished. I really don't want to screw this gun up experimenting. Any advice is appreciated.