Just hit down with a brickies bolter to set the form I needed. Step now extends to the end and just needs a bit of planishing and trimming.
Both sides done now. All lines up pretty well considering these two parts of door came off the production line 10 years apart.
I think the shorter door and wider pillar looks better. So the door is 115mm-4.5" wider than stock and the B pillar 60mm-2.5" wider. Ribs line up pretty well but there will be plenty of work to get it all sitting just right after welding.
I noticed before even welding the door together that there was a lot of crown in this part of the door. The ends look alright. You need some to stop drumming and oil canning. Checked the other side, which have not been worked on at all, and was the same.
I just used a 5" shrinking disc on my grinder to heat up a 4" square section at a time until it turned a honey colour and then quickly hit with compressed air to shrink it. Do need to be careful not to overlap the areas as you go along as it will create waves where it pulls more on the double shrink. I'll leave it at that I think as worried any more could cause a 'loose' panel where it flops in and out.