Im doing flush glass on my '70 Coronet.
We have world class glass maker here in Finland. Has made many world class custom car glasses even to the States. Kuttilan autolasi Oy-company, been making car glasses past 50 years..
I asked front and back glass from him. He sad that glass is cutted over a die. So if I drovide him dimenssions he can cut the glass oversize same as the stock one. No big deal.
I didnt fill opening, I just made new pieces with Pullmax.
Same as he will make me new door glass, full glass like in e-body Challenger but for my b-body. Without vent window and frame. Those are more triky because I want them to be heat threaded. Hardened.
EDIT: I didnt know they where in IG:
Link show a post with few custom molds they have in warehouse.
https://www.instagram.com/p/Bbvzrygh..._web_copy_link