The sort of good news is that IF the rangefinder is set up for for the 127mm lens that's on the camera and IF the infinity stops are there and in the right place on the tracks the camera would be perfectly usable as is with a Grafmatic magazine (holds six 4 x 5 sheets) or a roll film holder. It would be a huge hand held rangefinder camera, but quite usable and a lot of fun - I have to admit to sometimes taking the back that's missing in your photo off of mine to save weight when using it as a walking around RF cam on a monopod.

I thought that the Crown came standard with a 135mm lens and the Super came with the 127mm but I'm not much of an expert so I'll defer to others on this.