Wow, good work on the clearancing for the t case. I have been considering the same on my TJ. I did something similar on my old YJ, but I used a BL. Oh well.
Have a better picture of the hammering you did, top or bottom?
I just helped a buddy replace the drivers floor in his YJ. It was a lot of welding. I did most of it, heh! I wish he had gotten a fiberglass tub instead, but they are a bit spendy. Ah well. Next one, maybe.
I was wondering the same about the seam in the back. From looking at them, there isn't much you can do. Cover with armor, that's about it. The water gets into it from the back side, no matter what.