A couple of years ago, friend at the local state government Department of Sustainability & Environment gave me several (expired) 100ft rolls of this stuff that they had sitting in an office for aerial mapping activities. After collecting a heap of 70mm processing ephemera, I finally exposed a couple of rolls with a Mamiya back on a miniature Crown Graphic - you can get 50x 6x7cm negatives on one roll!! I found if I processed it like regular Plus-X the results were fine. Next time I might try stand developing (like Rodinal 1:100 for an hour or something) and see what happens...
This does inspire me to shoot the rest of my "stash" though, so in the interests of emotionally amortising all the 70mm infrastructure I've accumulated, please put me down for ONE roll Keith, and I'll commence saving!!!