The roll film for the cirkut attachment is 8" wide, as you said. Most cirkut attachment backs could also take 6.5" film by sliding the bottom of the roll holder. The camera itself was a full plate camera as you said. One issue was that the full plate holders to fit it were sized differently than a lot of other full plate holders, so you have to find the right size. The film was spooled differently than on the cameras that were just used as cirkuts. Emulsion faced out on cirkut attachment film, and it does help a little when trying to avoid banding.