Tri-X keeps getting quoted, but can anybody give a 7 digit Kodak catalogue code for perforated 70mm Tri-X film, which is reasonably easily available? Rather than looking for crumbs off the table, remnants from industrial 70mm applications, wouldn't it be better to try to get a steady supply of conventional camera films?
One reason for pushing the 70mm 'envelope' is it is at present a dying format, BUT the remnants are still around, plenty of 70mm backs, at least for Hasselblad, and it wouldn't take much to at least keep it hanging on in there. Then it is a viable alternative if various 120 films start to be wound up, principally because it can be cut from the same stock as 35mm films. Fantasising a little, Ektar 100 could be made available in 70mm format very easily!