Trying to identify panel behind front lower quarter

[jthomass]

Hi
I started working on my 72 Blazer and this is my first question.
Wondering if I could get some help identifying a panel. I cut out a chunk of the lower front quarter on the drivers side. It looks like there used to be a panel perhaps bolted to the front of the backside of the rockerbox. It is completely rusted, so I'm wondering if there is a patch made for this or should I cut off those bolts and try to make a piece to just weld in there? It seems like it is a much lighter gauge steel than the rockerbox. Any thoughts or suggestions would be appreciated. I hope the picture I attached will work.
Thanks