First up is a Mamiya RB67 6x8 Power back, works as expected, cosmetically 7 or 8 out of 10. I got it for a project on shooting 6x8 with my RZ but the light baffle was a bit too small so its not a perfect 6x8 image, but it is def. wider than the standard 6x7 image.
Im asking $100 shipped and PP'd OBO
Second for sale is the rare Mamiya G-Adapter, i hacked it a bit to make the opening bigger to suit the rb 6x8 back but it will work perfect with a regular rb 6x7 back, if you dont know its an adapter mamiya made to let photogs use RB backs on the RZ bodies.
Asking $40 shipped and pp