I just found an Argoflex Seventy five camera in a box of my late mothers stuff...

[hunter]

6. It's not difficult to develop your own film.

Don't lose the metal 620 spool!

120 film and 620 film are the same size except for the spool.

120 film can generally be made to fit 620 cameras by clipping the plastic edge of the 120 spool with curved nail-clippers. In a few 620 camera models these clipped 120 spools still won't fit correctly and may jam, but it works for all of mine.

If you have someone else develop your film make sure you trust them enough to return the 620 spool from your exposed film. 620 film spools are not unobtainable, but it's a nuisance not to have a few around.

There are still a few places left that sell 620 film, but it's a lot more expensive than 120 film, often because it is 120 film that's been hand wound onto 620 spools. You can do that yourself too.