Inner rear guard thingys?

Not sure of the correct term for this panel. It sits in between the inner guard and the outer guard to the rear of the front guard. Well whatever it is, it's had better days! This is the repair on the bottom corner.A piece of metal with a couple of snips to help it go around the corners and some random pop rivets.
After cleaning it all up. Below is all I was left with.


Now i need to get out the hammers and make a couple of decent rust repair sections. Will let you know when I've got them made.