Double barelled flintlock ottoman pistol

[eftihis]

Visiting a friend's collection, i saw this curious double barelled flintlock pistol. I have never seen a similar one! It has 2 different pans, and the one is movable.The way that it is operating is that you first fill one pan with powder, so to be ready, and then you slide the other pan and put it on top of it. You fill it with powder, fire the shot, and then move it on the side so that the lower pan is now visible and ready to be ignited.
IS this a european made arm that was meant for export in the ottoman market? Or it a known type of firearm? Also there are some sort of inscriptions on either side among the wire decoration, it would be great if someone could make a translation.