Hey, I love this project! I have the exact same lens and hadn´t heard about the front modification, seems really interesting! This is a bit of my experience with this lens and anamorphic in general. I have a pretty special grandpa that managed to build me an adapter made of methacrylate that fits the back of the Bell&Howell and converts it to a normal m49 filter thread. Pretty absurd, but it works. On the front I attached a 77 diameter diopter directly to the mattebox, and voilà, ready to shoot. Did a couple of test shoots with my GH2 and then I shot a short documentary with this on the