So I dropped by the upholstery shop today we did some test fitting of the panels. Overall, the stuff fits about as well as any aftermarket part for a 40 year old car. That is to say, some modification is required for about everything since no two cars are exactly alike. It took about three hours to mock up the headliner, but that was mostly because we had no directions. We didn't know we had to take these pieces out:

As of now the headliner side panels will need a little bit of trimming at the back base, but are pretty good.
Right now there's a bit of a gap:
another minor issue we've had has been fitting the rear door panels with the DSE cage, which hugs the car really tightly.
Lastly, here's a sample of the look for the doors

the fiberglass trim will get covered with this fabric:
Matt