thanks all.
Yes, mine is the one from the Leica shop in Wien. It is a lovely camera, on par with a Voigtlander Bergheil for quality and having an interchangeable lens facility. The Zeiss lens I have dated to 1929, so presuming it came with the camera (likely), it is indeed height of Great Depression time, as Ian points out. It is turning into one of my favourite cameras and at 80 years old pristine and working hard Just need more bloody 9x12 film inserts! But am using a Rada back too so great for 6x9 and 6x6.