Thank you.

Well, I have never seen them before, so I will try my best.

The sights are "normal" open sights, just mounted on the side of the rifle, adjustable up/down and left/right.
These had to be done, so the owner was able to use open sights. His right eye is now, do to with age, to weak to use the original open sights on the Krag. But, now using his stronger left eye, he is able to join us at the range. It looks odd, but it works just fine.

Hope I was able to explain it a bit. I will talk more with the owner and find out more, maybe some more photos to.