Use mamyia rb 70mmback-with vaccum-option -rzu-g-adapter needed and cut 70mm into 2 pieces. bhvideo has the alden 70mm bulk-film loader. with the 120-35mm-adapter one can at least use unperforated film. have a slitter to cut it out from 70mm perforated since unperforated is hard to get let alone 35mm unperforated.
xkaes at aol.com delivers the slitters, most of the time with multiple weeks or months production time.
maybe you could post a link to the sales-site. on original one -the pinholecam-makers-its not available.