I started fitting the rear seat. If you tubbed the rear end, you must cut the rear seat. The best way to preserve the hinge mounts and end of the first fold is to cut it in the middle. Yeah, that's right. Two cuts. And then weld it together. My fenders measured only 39" clearance and the panel was 41". It now fits pretty good.
And I had to remove the floor mounting brackets and re-weld them in by 1" each side.
Edit: I wish that I would have cut the panel off to one side or the other so the mounting holes in the new chrome pieces would line up. But I can alway just drill new mounting holes in the old metal for the one side of the chrome.