Before the Praktica, there was the Praktiflex. This camera was manufactured in Dresden by Kamera-Werkstätten AG beginning in 1939. This was a single lens reflex camera, with an instant return mirror powered by pressing the release button. After the war, the Soviets required cameras from Germany as war reparations, and KW made Praktiflexes for them. Dissatisfied with the quality and functioning of the camera, the Soviets appointed an engineer to redesign it. The new model was released in 1947, and was more reliable than the original, but had lost its instant return mirror, and had the release button shifted from the top to the front.
The camera above is from 1949, and still has the 40mm screw lens mount of the original Praktiflex. This was changed to 42mm in later production, and by 1951 the Praktiflex was replaced by the very similar Praktica.
The 42mm lens mount was called the "Pentax mount", but it was originated by East German Zeiss on the Contax S camera, in 1949.
I do have other cameras!