Here is another wrinkle or two.
All the Mamiyas you refer to can accept all of the grips mentioned, in that you can mount them on the cameras, but there are a couple of limitations.
For those grips that include some sort of trigger release, there are some incompatibilities.
For example, I had a left hand side grip that I believe was designed for one of the original M645s, but I found I could use it on one of my Mamiya M645 Supers, but not the other. It also wouldn't work on my Mamiya M645 Pro, or my Mamiya C330. The problem isn't with how the grip mounts, but rather with the physical interface between the trigger mechanism, and the (mechanical) trigger release on the cameras. All of these cameras have a trigger release in the same location on the body (bottom right corner, at the front) but the size and shape of the trigger release buttons varies slightly.
As far as I can tell, the RB67 and C330 trigger releases are identical in location, size and shape, so a grip that works on one should work with the other.
It appears to me that the trigger releases on my current Mamiya M645 Super, and my former M645 Super were significantly different so when I sold the former one, I made sure it was accompanied by the grip that worked with it.
Matt