Converting Auto Mamiya-Sekor CS 300mm f4 to Canon EF

I bought the Auto Mamiya-Sekor CS 300mm f4 for cheap on a flea market, but did not have a Mamiya NC1000 camera. This is why I attempted to convert this lens to Canon EF mount using my 3D printer as the flange distance doesn't differ too much from the EF mount. For this I changed one part of the Mamiya mount and printed an adapter which fits right in the cheap EF-M42 adapters, where the orange ring is detachable. This worked out fine, however, one mayor issue is the aperture mechanism, which is utterly weird. The aperture pin seems to extend when selecting higher apertures. This results in the pin extending into the adapter, such I had to drill off some material off the adapter. Now, the pin can extend into the adapter, but another issue came up. The pin needs to be pushed in for the aperture to change. Maybe I will try to add some silicone or some kind of rubber between the EF-M42 adapter and the aperture pin.