Zeiss built very few lenses with Leica thread mount, only during WW2, and only for the german forces. Henri Cartier-Bresson reportedly used such a lens for several years.
Please, have a look at the photos. The serial number and engraving indicate this is an original. The coating is blotchy, and there is some dust inside. Mechanics are perfect, the aperture and focussing rings work smoother than those of my newer Leica lenses. I had this lens CLA'd about 1 year ago and hardly ever used it. As you can see I added a 40.5mm Voigtländer UV filter and a vented hood.
Results are typical for a lens of that age, a bit soft, but very impressive. It seems as if the blotchy coating did not change that.
Price: 430 USD or 350 Euros.