I've just received a 545I that is made to go on my 600 SE Polaroid system. I've always wanted to shoot 4X5 readyloads in the big Mamiya. When I measured the d istance from the ground glass out to the body edge, and compared it to the 545's pressure plate with no film there is just over 1 mm difference. Not having any film packs here to compare with, I'm surious if the film support will raise tha t film 1 mm farther out or if it will be exactly where the pressure plate is now in which case I'll have a problem. Anybody know? To clarify, the 545 pressure plate is 1+ mm further into the camera than the foc using ground glass is.