There were several companies making, and/or modifying Polaroid backs, for a variety of cameras in the day.
The link below identifies a distinction between Mamiya backs and those made/modified by NPC and others.
It states that the Mamiya backs also require the "P" Adapter, while the NPC backs don't need the adapter.
Along with the advice of Alastair, (above), and the link (below), the non-Mamiya backs (NPC and othera) apparently had aspects of the "P" adapter, built into their backs for the RB's. The revolving adapter may need to be removed with either back.
With the absence of more experienced RBr's chiming in here, (I'm a RZ user) I would suggest contacting
reputable re-sellers like KEH, in Georgia, or B&H, in New York.
Don't bother with Adorama; they seem to be bothered with answering phone inquiries or emails: ie...they won't respond.
Last edited by Marc B.; 06-22-2011 at 12:07 PM. Click to view previous post history.