I've got a cromoly frame from the early 90's which has rust speckles on the exterior from being left out for a winter. The inside of the tube is in fine shape, and it's an awesome seafoam green, so I built it up for my girlfriend. I'm curious, though, whether there is a way to remove these rust spots without damaging the paint? I'd like to prevent exterior rust by scrubbing it off, using nail polish, and clear coating. The speckles are all about half a centimeter in diameter, the paint is pretty tough Schwinn paint, and I've already tried Simple Green and a plastic Brillo pad to no effect. Any advice?