The OP has been putting together his kit piece by piece - he may have bought the body with the intention of acquiring and using the power winder instead of the manual crank.
Many of the original Mamiya 645 Pro cameras were definitely sold with a power winder and without the manual crank. It may be the same for the Mamiya 645 Super.
Yaaaa... I know that. But to think the wind on the film back would cock the camera's shutter indicates a lack of understanding of the mechanics of the tool. Not his fault. Most people these days grow up with no knowledge of the technologies they use.