[rickst29]

First, let me correct some wrong terminology in your last post (please edit and fix it): Your issues are in the floor and the lower curb side wall of the non-moving lower box structure, not the shells. Replace your references to "shell" with "lower side wall", to avoid confusing other readers.

This bolted-to-the-frame outer wall support L-bar is not OEM, it is a previous owner's fix attempt. It supports the sagging floor from the frame, all the way out the the lowewr wall attachment. But is is only 2" wide (at the most): The floor edge continues to sag in front of the supported area, and (even more) behind it.

That bolt (at the end) may not be long enough to reach up into the side wall itself - and even if it were, it is possibly to big (diameter) to leave any side wall wood structure for supporting threads within the wood edge.

You need a fix for the entire front-to-back length of the problem, not just a single point with 1 or 2 inches of width in the "support".