Question for your contact at a $12000 approx minimum special order (40 x $300), would they cut a few different widths? Seems like a high minimum order though. I'm interested in 7" and 6.5" widths, for my al vista swing lense and 6 outfit cirkut. I might be interested in a roll of 10", but that's a drop in the bucket for the size order. And what base is it on? It should be on 120 thickness base. Have you checked other sources as well? It's sad that forte is gone, as their minimum order was much more practical.
On the 9 1/2 inch spool problem, you should make some spools to fit the aerial film. I cut some down for that and it works great.