Its upside down in the picture, but the "NC" That are overlapped, is the mark of Nicolas Carteron, an arms inspector at St. Etienne, around the 1740s-1763. I'd have to check about the other marks, most likely acceptance/ proof/barrelmakers marks..
The crown over the double entwined Ls is the king's royal symbol.
These are in the Kevin Gladysz book,page 156
Probably a post war restock IMO