Unless you have something I am unaware of, those old cameras didn't take 220 film. As you mentioned, there is no paper backing. I would worry how light tight the red window is. That is, the one used to view the numbers on 120 film. It is even possible minor leask which would be stopped by the paper backing might get through to the film without the backing. Point being, I just don't see any worthwhile way or reason to use 220 in these old cameras. If you do figure out a way, let me know.
Stay with the 120. There is more film variety anyway.
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