please help - kindjal signature !

[Rivkin]

Dear All,

I've recently acquired a rather nice kindjal. Looks like a georgian, may be southern chechen.
The signature seems to be in arabic (it's certainly not greek, armenian or cyrillic, can it be some really old Mkhedruli that I can't read ?). Unfortunately in any way I can't read it, so please help me if you can ! The photograph is attached, it's right on top of the fuller.