This is a second generation Praktiflex, made in the late 1940s. It has a CZJ Tessar lens, 5cm f3.5, in M40 mount. This camera is the direct ancestor of the Praktica FX. This particular camera came to me with a fault - the shutter could be wound, but the mirror stayed up. I had to strip the camera down to find the problem. Above the film takeup spool is a cam, which bears on a lever, to cock the mirror. The lever was running under the cam - a tweak with pliers saw it back in the correct position. The camera now works as it should. Since the shutter blinds appear to be without pinholes, and the shutter runs correctly at all speeds, I have loaded a film in the camera. I'll post some of the results here after the film is processed.