The issue I can see is the thickness of the paint. Almost needs to be filled with lots of high fill primer, or lots of coats of color, like original, 6 coats of enamel..if sands smooth, will be a bad ripple to blend...been like this for three years, no idea how to fix easily..
I would want to sand it an feather back anyway to be sure it was not going to pick up farther out in the future. Sounds like a lot of block work, but that would be my initial plan anyway. Be nice if you could get some pics and get @GeorgeH opinion.