69 dart

You need to remove ALL of the rust, then fill the holes with weld or new metal, depending on size. Once your bodywork is all finished, spray on a couple of good wet coats of epoxy primer, then some high build primer. If you're going to replace the vinyl top, then sand everything straight and smooth, and give it a least a couple of good coats of paint for future protection. If you aren't going to replace the vinyl, you may have to modify your chrome/stainless trim because you won't have the thickness of the vinyl when you go to re-install the trim, so it will fit kind of loose. Good luck.