I bought this jupiter 3 not so long ago for $200. As there is a Zeiss number, I guess some parts are from Zeiss. However, the coating is really unusual for a Zeiss lens (too pink and to blue) and the serial number is really late ... I used to think Jupiters were made of German components up to 1951. On the other hand, the low price, the numerous bubbles in the lenses and the fact that it is not a "ZK" tell me it shouldnt be fake...
At first sight, your lens is "normal" and belongs to a batch of 5000 1,5/5cm Sonnars made for Contaxes. Yes, the general idea is that German parts were used only up to 1951 for these lenses. But there can be exceptions (parts found well after in KMZ boards).
Another possibility: the replacement of the front part of the lens because of scratches or else. I have such a lens, in LTM and with a 1971 KMZ number. And with a Zeiss number on the triplet too... Probably a replacement.
Many thanks for your answer! I think you are right. I was just disturbed by the coating, for me it is a bit too pinky, not purple enough :). I didn't know it was possible to find a 1971 lens with Zeiss number, amazing :).
Hi, I managed to replace a very scratched front element on a 1938 Sonnar (Contax mount) with the front element from a Jupiter 8m. The lens resolution is absolutely fine, so quite possible to inter-change certain elements of lenses made 40 or so years apart.