I was asking, recently, about an old Kinax camera, and what to do with it. I decided I had to put at least one roll of film through it. I bought a roll of Ilford PANF Plus 50 B&W 120 film. I wanted a lowish ISO because the camera's shutter only goes up to 1/150.
I had read that the 120 spools can be modified to fit many 620 cameras, and sure enough - was able to do it. Turns out it is really easy, because the Ilford spool has thin ends with raised edges. I just cut around each spool end with toenail clippers to make the ends flush with the film roll. This removed the raised edges too, so nothing further was required. It fit in the Kinax snugly but easily. No problems advancing the film, even the markings on the film back line up with the little red window on the rear of the camera. I took a couple of quick test shots using the Sunny f/16 rule.
Now to plan how to use the rest - I believe 12 exposures per roll is normal for 6x6, but this camera looks rectangular - perhaps 6x7, so I will get less.