Nice work-interesting to say the least! Have a couple ??'s. Remember well, fitting the w/s in a 66 cvt after changing both hinge pillars, along with MAJOR cowl rebuilding. Fitting the w/s was a major deal. Had an old w/shield to use for fit. Had made templates to use prior to welding but still wanted to see it resting in place without rocking or whatever. Did you check the rear window area for fit prior to welding in roof skin? Did it need tweaking for rear window not to rock or chafe, fitting like an original?
When replacing those hinge pillars, my replacements were good used pieces, but had bare metal inside though not rusted through. Did you rustproof those pillars and boxed sections over the doors on the inside?
Again, very nice, looking forward to seeing the finished product.