As a test, I polished of the gold plating on a set of Buck Stoves cast iron legs. The gold plating looked spotted and I could not clean it. I took some brass polish and noticed that underneath the gold plating was some nice nickel plating. I got ambitious and took a buffing wheel with some polish and removed all the gold and now I have a beautiful set of nickel legs. A friend of mine did the same with a set of gold plated doors for a Fireplace Xtrordinair. He polished off the gold and the doors were a beautiful nickel. Apparently nickel plating is the base for gold plating.
I am not telling you to do this with out testing a small out of the way spot first.