Really nice looking gun. Will need pictures of water table, barrel flats, the usual advertisement do-dad stamps on the barrels, any maker stamps, etc. Assume the barrels are the French standard 27.5" (70 cm) and the chambers the mostly usual 2 1/2" (65 mm) (If the gun has been in the USA, check to see if chambers were lengthened, a common occurrence).
The checkering on the half-pistol grip is very French - it is skip line checkering creating a Scottish tartan effect. Wingshooter many years ago said it was called "quadrille Scottish" In fact that would be "quadrillage écossais" - the term for Scottish tartan - in French and used to describe the checkering on stocks.
Chokes likely will be Full/Full unless it has been in the States for awhile.
since you mentioned Jean Breuil, here are a couple of barrels you can reference - note: one of them is chambered for 70mm:
![[Linked Image from i.imgur.com]](https://i.imgur.com/ud5spyR.png)
Here is a post 1955 Jean Breuil for sale on Naturabuy:
https://www.naturabuy.fr/FUSIL-CHAS...s-bon-Categorie-C-XXe-item-12482127.html