Gene,
There are plenty of French boxlocks out there, usually 16s, often with short chambers, and even more often for short money. "Out there" in this case refers to guns that are already in the states, that have had the owner "age out" of, for lack of a better term.
You don't have to import anything. The gun buying/selling dynamic has changed completely since I was last in France, but, in the mid 1990s, guns I could get perhaps $500-$800 for, here in the states, routinely sold for $1200-$2000 in France. Rich people hunt in France. A lot of times, a son or daughter inherited a mid grade French gun, and simply sold it to recover the windfall, rather than screwing around to find/pay for a place to bird hunt.
The gunmakers I was working with would go years between hunting trips.
It was a different story with pigs, which, seemed to be considered a tasty pest, from what I could tell. Farmers were happy to be rid of them.
I truly believe you will do better, here.

Best,
Ted