Not legal to own, neither to carry !!!
sure, it is on some french catalog, but NO french prefecture will ever release an autorisation for such a knife/gun.
As you may not know, in france NO WEAPONS permits are delivered for defense or collection..
The only way to get guns for french is hunting or sport... and this weapon don't fit one of this category. No prefet will ever allow a normal citizen to own such a gun.. not even dream about carrying.-