I traded for a M60 pro. It has the stainless satin finish. The gun was like new in box except it had a set of rubber grips put on it. I went to remove grips and found some tarnish along the left top of frame where grips covered. I was able to rub out some of the tarnish but not all. Is there a way to remove this tarnish and keep the satin finish. The new grips I am going to use will not cover all of the discolored area.