Using 120 Film in a 620 Camera
There are many old cameras that were made for type 620 roll-film which is now obsolete. Some 620 models can readily accept the 120 spools with no problems while others require some form of work.
You can revive these (often cheap) beautiful cameras by:
A. Respooling 120 film onto 620 spools. This is pretty straight forward since 120 film and 620 film are of the same size. You just need to have the 620 spools ready and do it in a dark bag.
B. Modify the existing 120 spools. This is easier than it sounds.