I don't know this camera specifically, but you have a 6x9 folding camera, which uses 120 film (still available). You should wind the film to the end, and if it's black and white film, you should have it processed and see what photos are still on there.
If it is like the one in the picture, I would think the value would be between $30 and $50 at most, and that's because you have the original instruction manual. I'm not sure how much that would be in British pounds or whatever your native currency is, depending on whether you live in the U.S., U.K., Australia, Canada, etc.
I think this was made after World War II and was exported from East Germany. I think it's from the late 1940s or early 1950s, but others will be able to provide much better information.