I recently purchased a ’70 Chevy C10. The original owner’s son had it spray painted gray after his father passed away. He didn’t like the original color which was the dark yellow and white combination. The paint job wasn’t a professional one and some of the gray paint is coming off revealing the yellow and white underneath. And, the original paint is just like new. Is there anything I can do to remove the gray paint without removing the original paint? I tried a rubbing compound and it just may the gray paint shine.