The rifle barrels have 45-90 stamped on the top rib, I am assuming the rifle barrels were built latter as they are sleeved shotgun barrels and have zero proof marks on them anywhere.
The watertable shows a X with a star above it, that leads me to believe that the gun was built between 37 and 64, if that is the case I cant believe it is not nitro proofed along with the lack of proof marks. I have been scouring the internet looking at pictures and I can not find another Francotte gun that looks the same.
thanks for the help, great information.