Only easy fix I could matbe think of is cutting out the old ones and reforming some new sheet
metal in there. Or get the dents out as best you can and a generous layer of bondo, then sand. You could get a decent shape out of it. The I would go with the rhino liner. Rhino liner is tougher than paint and almost like adding armor to your truck.
I'm thinking of rhino linning the inside of my truck since it always gets muddy.