The lock is not a "Nicolet", but rather a "Miquelet" or "Miguelet" (both spellings are common). The lock form is usually associated with Spain, but nobody can say for sure where any particular lock form originated. There are two forms of this lock type: 1) the mainspring (exterior) bears DOWN on the toe of the cock; 2) the mainspring bears UP on the heel of the cock. Both work acceptably well. I have seen miquelet pistols dated as late as 1812 (Spanish). There easily may be later ones, especially the farther East one goes. This particular lock is rather odd in that there seems to be some sort of shield over the mainspring, and it looks to be built on a European lockplate. Possibly an example of a gunsmith improvising with what was at hand...a common enough phenomenon.
The stock is definitely of an Eastern type; without handling it, it's hard to say, but I think it's the type which is not butted up against the shoulder, but simply held alongside the cheek. I would be very surprised if the weapon were rifled; rather it is probably a sporting smoothbore, built for relatively light loads. Too much decoration for an arm issued to a soldier. It DEFINITELY should be looked at by an expert, at close hand. These photos are good enough for a quick guess, but it has to be held in the hands to be able to really "talk" to the student. I would be extremely hesitant to fire it; the barrel should be thoroughly examined.
