Looks like a Petri lens mount according to the second link above, it has the same lens position protuberance on the lower left.
+1
The images I've seen of the Petri mount seem to be identical to that lens, however the aperture lever on your lens photo seems to be missing. Perhaps it's an earlier variant with no Auto-Aperture capability, or it may have been modified (removed) for use in video?
Interesting lens though... if you've got it, it would be nice if you could post some images from it.
Welcome to the forum btw, Infinex!
