It would appear something was hacked into the bumper mounts (both sides) with a nut welded to the frame. Perhaps some sort of home built tow bar ?
The lower slot was hacked open to clear behind the welded nut. Another Green Bastard repair issue.
Clean up the damage.
Fab up a patch coupon.
Back with copper and weld in. I was using the Tig again just because I wanted the practice.
Finished up