Hi Norman. I've been away from the Forum for a couple months. Just now catching up on all the great gun Posts. That is a very interesting gun you have. My observations/opinions: 1) The stock is done in the Caucassan style, especially the butt area. 2) The barrel looks more Ottoman/Turkish in style. Especially the design of the rear sight and the barrel tang area. As well, the "bottom groove" rifling was most common (but not always) with Turk made barrels. Of course the barrel marking/translation may prove me wrong. Which just adds more interest to the gun. 3) The lock as mention above, looks more Balkan - even Persian - in style. 4) The bone inlays also look Turkish in style. Attached is a pic of a Ottoman Tufak Rifle I own. Note the similarity of the wrist inlays with yours.
I think Teodor offers a good plausible explanation. Maybe my comments will just add to the mystery?
Taken as a whole, this is a really neat gun. I wish I owned it. It's so very interesting. Congratulations. Let us know if you receive any translations, etc. Rick.