I have inherited a 1911 that has a nickel plated finish with pearl grips. This gun has been left in the safe wrapped up for the better part of the last 40 years. The surface has developed a slight gold tarnish look to it thru the years. There is no rusting or pitting or wear of the finish. Is there any way to restore this finish without destroying it. I have tried wiping with oil but nothing stronger. Thanks for any information.