This is not an RPG launcher, it is the shoulder mount with camera and lens mounted that my father used for his photography. My father made the shoulder mount from a piece of beech wood to be able to support his camera during the wildlife photography he enjoyed. He got this gear together around 1959 or 1960.
The cable release was integrated with the pistol grip of the mount for ease of use and the combination with the Pentacon-F camera and the Tamron 400mm f/6.9 lens he used was well balanced and easy to use.
For years he would disappear all Saturday afternoon after work and get back to disappear again into the darkroom. At the time, the fastest film around was ISO 400 film. Imagine using a manual camera with an external light meter, manually focussing on the ground glass and a 400mm lens at f/6.9. No surprise that he used to push the film as fast as he could and solely rely on his experience to guess the exposure and correct for any underexposure during development.
Yet the results are not overly grainy and well exposed, see here for an example.