Hey William, just delt with the same problem on my Marquis, I was going to order new ones, but then decided to pull them out and paint them, they were a tad rusty on the ends that go into the slots and at the back, just scrubed them down with a red scotchbtight and gave them two coats of a quick drying rust enamel , and they turned out awesome. if you were going to go to the trouble of stripping them and powder coating, I would just buy new ones from Thetford, they are only about $18 bucks each ( I am assuming you have a Norcold, if not you could get them from Dometic )
Dave