I say chemical strip and get the stubborn spots with a 4 1/2 grinder and a paint stripping disc. Then go over everything with 80 on a DA. Fix your dents at this point (filler),then Epoxy primer (2-3 coats and guide coat n block w/ 180 touch up any spots with metal showing) followed by 2k High build (2-3 coats guide coat n and block 320 dry then 500 wet) followed by paint.
If you decide to strip with 40 grit be extra careful of heat buildup especially on top surfaces, you can warp them.
Please correct me if anything I said is way out in left field, trying to learn also.