The '78 Z28 dash bezel has what appears to be a metal overlay. These get tarnished with age and get what look like mildew stains on them. How would you refinish one of these? Wipe on some Tarnex? Try to peel the metal piece from the plastic frame and polish with a dremel? say to heck with it and mask it off and paint it? I hit it with a wire brush and my dremel but didn't see the results I expected. Anyone restored one of these before?