I've been making photos and collecting cameras for more than fifty years and I have only seen one "in the flesh" - at a camera show, where it was displayed but not for sale. The kind owner allowed me to handle it and fit the lenses for me to look into. He asked me not to fire the shutter because of its age and the availability of parts, so I did not try that.
My impression of the camera's build quality was that it was extremely high, difficult to achieve, I think, in postwar Italy, but that the material and finishes were first rate. The telephoto and normal lenses I tried focused smoothly and also appeared to be high quality. The unique mounting mechanism seemed well made and a highly functional design.
From the research I've done on this since I had that opportunity, I have seen only a handful on the market, and at very high prices. I am an "eat off the good China" kind of guy, and I personally would not buy a camera as a collectible only, but I would be extremely reluctant to do much shooting with one if I had the opportunity to acquire one, even at a reasonable price. There are so very few left in the wild, and each one is a nearly unique example of photographic history. I had hoped the owner would be attending the next local PHSNE show, but that has, sadly, been cancelled due to the COVID 19. If you ever find one again, I'll happily give you triple what you sold it for, but I'd be surprised to find one whose owner didn't understand its value. A grail camera for sure, but one that even I would be afraid to load up very often.
Andy