I just did this a couple months ago, had same issue, rusty with pitting on the bead area. I blasted them first with heavy grit media, then with fine media to smooth out the finish a bit. Then I went after the imperfections with a side grinder with flap discs to smooth the bead and the damage on the front side of the rim from (Po) Mr Curbie parking by touch. I layed down the primer on the thick side and sanded and primed several times to reduce the depth of the pits, then did the same with the paint. By doing a light grind/sand on the bead, then building up the low spots, it reduced the depth of the pits by about 80%, and they are smooth enough to seal just fine.
It took a full 8 hour day to do the blasting and smoothing of imperfections, then another full day for sanding, priming and painting. Then another day for the center caps and trim rings. It was way more time consuming than I thought. It would have cost far less to pay to have it done. But I did take pride in restoring them to near perfect condition and don't think they would have turned out as nice if I just dropped them off somewhere.