The rear window isn't done yet, it'll be one of the last things that gets done, they need the window holes while they work on the pantera hatch. The metal guy and I have a few ideas. The first is to start with a plate cut to shape, and then weld rods onto the plate, spaced the same as on the hood vents and the cowl. The other option is to cover it all with a metal mesh, like grill mesh, this would work with the aftermarket msa hood vents. Luckily you can fit whatever you come up with into the recess created for the window. For glass, you could probably go to any good automotive glass shop and they can cut some tinted tempered glass to shape for you.
The interior ? LOL. The inside is all going to be custom anyway, with the pantera hatch and the window mechanism out of a Del Sol, it's going to be very non-stock.