Mystery Optics

[diopter]

We're stumped as to what this B.U.F.F. of an optics is.
Anyone have any idea?
Pak Gun sight, RCL rifle sight, Mg sight, theodolite, naked Elcan variant?

Original post.
http://theswissriflesdotcommessageb...nd-on-the-web-and-its-no-doubt-for-a-K31-just

 

[HumanCulling]

I saw this on the Swissrifles forum as well & even Guisan himself did not know which was surprising.
I haven't a clue BTW.

 

[B2012]

spotting scope? diopter anti glare? funkaaaay red dot? Flashlight holder...lol good luck with the quest!