I've tried 120 in the past; the spool rims are too wide; won't jam in no way. Since I was on Rollei model I mode today, I cut the rim off of a 120 roll and it fit in the bottom spot. Since there are no pins there, it rolls in a kind of Flintstone way and will pop out due to the irregularities. With the door closed, success. I then placed a 620 spool in the take-up spot (narrower diameter spool rim, tho' a bit loose) and voila! I just got in the door from shooting a few frames.
I'd still like to try a 117 spool in the take-up spot, but I'm pleased with this progress. I'd prefer to use a camera now and again than to have it only living on a shelf.