I just scrolled up and saw top photo :rolleyes:
It’s just badly fitted rear flairs , with bumper modded to suit the bad fit imho .

Easy enough to fix .
If not easily visible from underneath (they ussually are) Use a magnet To find where steel ends , and cut off and redo fibreglass .
Most were done by laying over metal and riveting on , then glassing joint before grininding rivets and finishing .

Though I’d preferably buy a new rear bumper first that was known to be a good fit , and work to that .