I've gotten some info from Olaf Matthes via email. He doesn't have a account on this forum, but let me post his answer. Maybe someone else will find it interesting, like I did.
Here's the quote:
"I don't have that much info on these lenses, but I do have a 35mm Cinar. Overall construction looks similar to your 8mm lens. My understanding is that some time in the 1990s Panther got these lenses custom made in small batches. Since there is no 35mm lens in the Zeiss lens set for Super16 and since the 8mm Zeiss lens would not cover Super16 it makes sense to get such lenses custom made to complement a Zeiss lens set. There also was a 7mm Panther Cinar.
Back then Panther was a rental house for cine equipment. So they probably got a few made and rented them out. In recent years I've seen them showing up on eBay from time to time. Mostly the 8mm and the 7mm lenses.
From looking at these lenses, I'd say they were manufactured by what is now Optika Elite (or Optica Elite, depending on how you transcribe the Cyrillic letters) in St. Petersburg, Russia.
Here's a link to a website showing Optika Elite lenses that were made around the same time (befoe they change to the new lens housings): http://www.reduser.net/forum/showthread.php?121883-Optika-Elite-Super-16-t1-3-Superspeed-Set-%28PL-Mount%29
What's another hint on the Russian origin is the shape of the iris blades. I have an 8mm Optar Illumina that seems to have the same iris blades like the Panther. They have a strange shape that gives a zig-zag pattern when half-closed.
The Optar Illumina lenses, however, have slighly smaller lens housings (that also feel a little more "edgy") than the Panther Cinars. That's why I think the Panthers were made by Optika Elite. But maybe Panther just asked them to use another housing, resembling the Zeiss lenses. So lets say the Panthers are either Optika Elite or maybe Optar Illumina. Some people say that today's Optika Elite company was a split off from Optar Illumina, so basically they share the same history (and thus similar design)."
I'm also attaching an image he sent of the iris. My Panther Cinar 8mm have a similar looking iris.