Barry says:
The whole of the nearside of the car needed to go forwards a fraction, so I did this with the Porta-Power. This corrected several problems all at once.

The next issue was that the rear was slightly bent over to the nearside. This was corrected by means of drilling, bending and welding on a 3mm steel strap for the dozer to grab. This worked well, and if the need arose, the plate could be cut off, the welds linished and the rear slam panel none the worse for wear.

It was then time for some more work on the back end, this time in a vertical direction. I'm omitting a bit of detail here - Barry is extraordinarily (in my view) open about his methods, but this bit has a couple of trade secrets.

Anyway the news was good:
As hoped, the nearside was lower than the offside, which explains why the front screen jig fitted as it did, pre-pulling.
The rear nearside being lower than the offside pulled the roof back, pulling the A-pillar back away from the jig.