I've been trying to convince myself out of having to make up a jig to hold the body level (stop the sag). I'd braced the interior along the way, so thought it would all be ok, but I've got to the point where I need to check the panel alignment before I weld the out wheel tub on, so I can weld up the repaired roof/door frame sections. After talking to one of the guys that owns a resto shop nearby about something totally different, I managed to talk myself into making up the jig.
I spent the better part of this week building it - using the height measurements from the manual. I made up the rear mounts, then the front - these gave me my fixed points. There was a slight twist drivers front to rear passenger that I pulled back inline.
Turns out I had quite a bit of body sag - I had to lift the middle/rear mount 45 mm (a little over 1 3/4"), this in turn brought most of the middle/front points up.
So after trying to convince myself that it wasn't required, I'm now very glad that I did!