Filling the pits on the frame, then POR sounds like the ticket. How do you prep the pits? What filler should be used b4 going over it w/ POR? Never done any body work. Thinking about using naval jelly on the pits, then using a screwdriver, ice pick, or anything to remove as much rust a possible. Then wash/ rinse those pitted areas, then heat them up a bit with a propane torch to rid trapped moisture. Must the pits be 100% rust free b4 applying filler?