[ariel]

You are right: Khevsuri, Georgian and Daghestani sabers (of the so-called Iranian type) did overlap: after all Khevsurs straddle the border between Georgia proper and Daghestan.
Here are some pics from Astvatsaturyan
:
#1: Khevsur saber and Palash
#2:Georgian sabers
#3-4: Daghestani swords (sabers included)

All have "shamshir" type handles that, unlike Persians are oval in section and get progressively more narrow toward the pommel.
There is no argument: they look quite alike. But look at the belt rings of the sword in question: they are not round like Khevsuri, but "heart shaped" like Daghestani. The vegetal pattern on the crossguard and the drag are Daghestani, not Khevsuri, in my mind: the latter used crosses and just multiple points.
The handle looks authentic in superficial form but is far too intact, shiny, and the rivets are covered with horn buttons. Those should have fallen out long ago. Astvatsaturyan specifically mentions that Daghestani sabers only rarely had horn handles and that the handles often had an image of dog's, horse's or dragon's head carved into the end of the pommel. It is not there, and the tip is not "capped". The blade has no markings. Even though it looks real, the absense of markings is suspicious on the blades from this part of the world.
Overall, I have far too many doubts about this sword: it is partly authentic but there is too much uncertainty and too many nagging suspicions and inconsistensies about it. If I bought it, I would have looked at it time and time again and trusted it less and less.
One of my colleagues once married a stripper. Divorced her in 6 months to a year at very high financial cost. A cautionary tale for impulsive e-bay buyers.....
On the other hand, look at the ivory-hilted saber on pic. #2: its twin recently sold on e-bay, and I missed it...... A real Georgian saber made by Purunsuzov or Eliarov at the beginning of the 19th century in Akhaltsikhe. I am still kicking myself......