I'd use toothpaste and a soft cloth to do a little polishing/cleaning. It's a trick us gunsmiths use sometimes when working with heirloom firearms that we want to clean up a little without disturbing the patina. Cleaning/polishing old guns can dramatically reduce the collector's value, sometimes by half or more.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!