I'll jump in here. I reached out to DB Engineering for my slant back, and had a wonderful man call me almost immediately. I asked if they could cut the material if I supplied a drawing or template, was told no. "We will not be able to cut your job.....way too busy in production. Most of our jobs are 100+ parts." His voicemail basically told me to take a piece of cardboard, trace it and cut it out myself. I'm continuing to look for other options.
I was told by several people about another gentleman that sells turrets. He just recently mentioned that he has headliner material cut to the correct shape and size, so I will likely pursue that route. Just a 2022 update. Once I have feedback on the new headliner option, I'll update here.