There has been a great deal of discussion over the years on the swords of the Khevsurs, and it seems there are a number of very well informed individuals here concerning them. When I first became interested in them over a decade ago after acquiring my first example, they were simply a Caucasian anomoly generally grouped among Georgian weapons, but seldom distinctly identified. The Khevsurs are of course, proudly Georgian, but prefer to maintain their distinct identity.
The initial information that I found on them was the material in the famed adventurer Richard Halliburton's 1930's book "Seven League Boots", in which illustrations and detailed data on the Khevsurs appeared. Subsequent efforts to discover more through Russian sources revealed little, until I acquired Astvatsaturnians book on Caucasian weapons (pretty tough in those days for me as my Russian is pretty rusty
uh, non-existant!).
Askhabov's book on Chechen weapons has pretty good data as well.
It would be interesting to see specific questions or examples posted on these, and I'm sure those interested will respond.