Agree with Jeager--this one might be old. It doesn't have the deep
curve or REALLY wide butt of the typical Jezail, but that doesn't mean much. The Snaphance lock was pretty much replaced in most of the world by the Flintlock by 1700---
Except in the Middle East and Africa. There it stayed on---clear into the
20th century. They are really hard to date. There are some regional
differences in style and choice of decoration, but no really set pattern.
The guns are literally a lock, stock and barrel. The locks are the hardest
part to make, and get reused on "new" guns down through time. So you
might end up with a 1650 lock, with a 1920's Belgian barrel--stocked
by Habib the camel trader with a piece of wood that washed up from
a shipwreck. As far back as you can trace it in your family--it's at
least that old.