It took a lot more work than expected, but finally managed to get tub/doors/bulkhead/steering/vertical bulkhead support brackets to all work together. Surprisingly little can make a big difference down the line. Everything is now nice and straight. Had to adjust the holes in the replacement footwells by a few milllimeters, and there will be some small shims needed between the tub rubber buffers and chassis support brackets. I would have prefered that the tub sit directly on the chassis supports, but there was absolutely no way that could happen and have everything else line up. They weren't touching on the original chassis, either, and so I guess that's just one of the idiosyncracies of this particular Land Rover (as are door curved sections which do not line up with the curves on the bulkhead; not by a mile). As well, the middle cross member brackets to which the tub attaches are way out, to the point where either the mounting points were different in a 1960 model or the chassis manufacturer made an error, and so new holes will need to be drilled in the tub there.
Once the last few details are taken care of, the last areas of the bulkhead can be painted and then all those completed parts in the storage area can start to be re-installed.
Driver's side door is schedued to have it's two frame cracks welded on Monday, if all goes well.