Good points all around. Yes, I will remove the cage to do it right. I didn't realize it was just 4 bolts to get it off back there.
Ron, I'd take your red capping, but clearly I have no contacts to get you galvi in its place. Maybe you want Dave's.
I really just want that left rear piece in clean condition. I can strip and paint, I just want one that's straight, clean and rusty-free!