i swapped all the backs and got 3 of the 4 of them to wind without shredding ..
i noticed i had 3 backs with a stationary pressure plate and 1 with a plate that is
kind of springy, so .. i let the 3 OK ones be, and then pryed off one of the stationary
plates ( vulcanite glued on the back ) and rolled up a piece of duct tape put the plate inside he camera
then the back on to position it... when i stuck my expired roll of cn400 in it to test ... it did the trick
so, if anyone else has and wants to use one of these weird cameras ... but the sprocket wheels are chewing up the sprocket holes
remove and make the pressure plate well, less of a pressure plate ... now i have to run some expired film through all 4 cameras.
its gonna feel nice to see, even if they are crappy, the photos these early 35mm cameras make.