I've been trying to restore some of my old G1 figures and have found that there's rust on some of the metal parts. I've tried disassembling figures and scrubbing at it to clear it up, but it can only do so much. And there are certain parts I can't figure out how to disassemble without outright breaking it (such as Optimus Prime / Ultra Magnus' hip/waist assembly). Some have been exacerbated by exposure to hydrogen peroxide from previous cleaning attempts, too. :/ In cases where the rust is just on the surface, does anyone have any suggestion for clearing it up if a scrub won't do?