and so the panel buying begins...
just ordered a complete Heritage passenger side inner wing. I think the plan will be to fit that, a complete door pillar and apex panel in one, door step, together with a bottom edge repair going all the way down the side over the rear wheel arch to keep everything spaced correctly. Then, move up to the section between the door and the roof line, which I believe I can use a modified door step to complete, and then work down the rear door section with new inner and outer B posts.
the two rear sides, except the lower few inches, seem to be pretty solid actually so I'm going to see if they're fixable. They do have a number of holes from the fixings for the fortech arches which will need to be plugged in some way.