IIRC it was VXorado who dropped the fuel tank. Maybe send him a PM.

I believe that the shield is welded on so you'd be better off trying to paint it while it's still mounted. Removal of the rear bumper cover is a bit of a pain but it'll give you clear access to get everything cleaned up & painted. The instructions for removal of the rear bumper cover are located in the How2 for insatlling a hitch.