I've read that the power winder for the 1000s can be made to function on the 645e. When Mamiya USA used to maintain a 645 users group on the internet, they were surprised to learn of this
.
If the 1000s power winder can be can be made to function on the 645e, one would guess that the rapid winder for the 645e might be made to function on the 1000s - as long as:
a) the connectors between the grips and the cameras are compatible (and in hand); and
b) there are no physical incompatibilities (protruding parts of camera or grip) that get in the way of each other.