I recently bought one to replace the slitter I made years ago (1958) from razor blades and bits of cork and sundry trash.
From a 120 you can get 4 x 15.6 mm slices and the camera won't even know!
It's almost harder getting 120 round these parts lately.
The tank was modified as said, to allow the 16mm to slide right in and suggly sit there.
One from 1959 as a student (still learning) FP3 in a Beutler dev. in the original Minolta 16. Forbidden to take pictures but who would've guessed it was a camera?