How did you rig it like this?
A 35mm roll fits pretty snug into the Koni's 120 back. I taped the roll into the back and the film lead to the 120 spool. Operate as usual, but stop advancing your lever once you feel ANY resistance. Toss it all in a dark room (or darkbag) and manually wind it back into your spool. It's pretty straightforward, even if it sounds complicated when written out. Thanks for taking an interest! (Also, I think I need find my negatives and figured out what film I shot, because I'm positive it wasn't Portra.)