Its quite a story, but I got this lens along with several other fantastic FSU and GDR camera stuff from a person in order to repair his Leica IIF. My Cyrillic is not that good, I somehow guessed.
After some puzzling I came to the conclusion that this has to be a lens for a Cine camera. It tried it on my Zorki 3, the lens register distance was correct (28.8mm) And the lens has rangefinder coupling.
Sorry for the bad images, its a very cloudy day here!
This is a soviet high quality cine lens with the classic Zeiss Biotar design. Spelling is correct Lenkinap OKS Lenkinap is the short name of Leningrad Kino Apparatus OKS is the short name of Objective Kinos'emochny ( translated as Cinema lens)