I think that Teleoceras is right on the money with the identification as an Italian Snaphaunce. It's what is for whatever reason called "Northern Italian" though I understand they were more popular in the middle, i.e. Tuscany, etc. Anyway, just from a wild guess/gut feeling I would say that it's probably 1750-1800 from the looks of it. MAYBE earlier, since it looks as though it has the tang screw coming up from the trigger guard, but since I don't know enough about Italian arms to say, it might just be a local tradition that hung on. The rest of Europe put the screw in from the top from around 1700 on (usually).
Looks too as though it was "Sporterized" at some point, in other words someone cut down the stock to make it a half-stock. Thus the weird brazed on ramrod pipe. It SHOULD have a band just like the rear one that still exists, made of brass. The iron ramrod is also a more recent replacement as well, though probably during the working life of the gun.
Anyway, I hope this helps at least a little. It looks as though it was a good, serviceable hunting gun in it's prime, and saw LOTS of use over the years!
Cheers,
Gordon