I have since discovered an interesting fact: the Accura GG Focusing Screen depends upon a MINIMUM camera aperture of 35mm x 24mm.
So far I have found that the Petri 2.8 Super Color Corrected (35.33mm x 23.35mm), Petri 1.9 Super Color Corrected (35.32 x 23.43), Petri 7s (35.15 x 23.21) and Fujica V2 (34.95 x 23.44) rangefinder apertures will NOT work with this focusing aid.
However, the Retina IIc (35.00mm x 24.04mm) will accept the device.
I need to measure more cameras, but the trend so far is that Japanese Rangefinders have smaller apertures than one German example.