The compilation of this document has been greatly assisted by other users who have contributed missing details or clarified points of uncertainty. Their time and trouble is greatly valued. The following people have declined their chance to remain anonymous. The compiler gratefully acknowledges all assistance, whether named explicitly or not.
R. Alford Rear lens cap information, wind-off feature
L. Blauner C220F details
S. Geyson Body cap image
T. Griffin Seikosha-MX lens information
J. Hanlon C3 details
J. Hein Various details for C330f and black lenses, finder scaling, exposure compensation.
S.Kantrowitz Illustration of C33 with 220 back.
K. Kirch Mamiyaflex and MX lens information.
R. Kirk C3 and C33 information.
R.Rosenberg C33 details, 55/65 compensation screen
Han Verhulst Porrofinder illustration and various obscure details and measurements; Single Exposure Back information; C33/C22 variations and dating; letter codes; chrome shutter variations; extensive research.
Greg Mamiya-PF pictures.