I just found this:
Mamiya RB67 Polaroid Film Back w/ P Adapter. Inside looks good, rollers could use a quick cleaning. This film back shows minimal signs of wear, most of it is on the back. Light seals are also starting to wear. Overall this is a great back for your RB67 Camerea.
Will this actually fit my camera? the url for the images say its for a hasselblad.