Oh that what looked like a panel or suburban rear wheel area, the patch to use there is a fleet side panel, that whole lower area is the same on them all, and would fix all that other mess that would need fixing using that patch panel in the photo.
Kicking self for selling off my Taskforce trucks. Still looking for an LCF or conventional big bolt in decent shape.
As of 10-26-2022, A 55.2 Taskforce long bed now the work begins