the webpage doesn't work beyond the intro page. tried different browsers...
I heard that the lenses are the week point of these cameras, with exception of the latest models. Maybe one could put there a modern equivalent of the original F length, the camera is adjustable in the focus distance.
Our friends at Surplus Shed have a sweet Metrogon 160mm
lens 90 degree coverage with 9x9 inch coverage which would translate to 6cm x 30cm on 120 film. I'm tinkering with adapting a speed graphic, rear shutter, waterhouse stops in the lens and blackening out the white structures in the lens (because it was a projection lens) Total about $150-$200 if you make film holders out of old 4x5 cut film, butted end to end... hand tool work.