So I'm finding out this whole restoration thing aint as easy as you and your peers make it look! Check out the new floor.
First, the fender mount bracket bottom tab doesn't slide down through the rocker like the old one did. Old rocker was spot welded through outer rocker, then tab, then inner rocker. Trim tab or cut spot welds in rocker and weld as original?
Second, it appears I have the same problem in the drivers rear. Tab (inner/outer wheel wells) that slides into rocker is too long and bottoming out inside the rocker. I'm going to trim that one.
I think the tunnel misalignment is from the front rocker problem and will see if it fixes with what you recommend from the first pic?