Looks like French manufacture to me (at least the barrel anyway). IIRC the french once used such fluerdelis for proof marks & a crown to show french service. Quite the interesting piece you have there.
Hope this helps you...
Not to be sarcastic, but try inside the barrel... Is it rifled? What's the approximate bore diameter, ect. This information can help to narrow down it's age, and/or origin. It looks as if the lock may have had some repair work done to it, and could quite easily have been from another weapon - possibly even of flintlock origin. Hard to tell. The stock has definately recieved some serious repair work. As far as other sources of info...there are many.
Start with a google search of "historical french proof marks". IIRC, you should find a .pdf that list's a multitude of proof marks from various countries across the ages. There's also a few books out there that cover such aspects. (Some are which are listed on the same page from that google search). I don't know about your area, but here there are at least ten different books at the local library covering deferent variations of lock assemblies...
I don't have the titles right off the top of my head, but if I come across them in the near future, I'll post them here for you.
Hope this helps...
FlDiveCop71

It is a smooth barrel and I can't find any more markings on it. I cant get a bore diameter cause the rifle is sitting at our cabin in CO and I'm back in NV.
Could be what was classed as a Fusil de Chasse. Or game gun. French smoothbore mosltly for fowl hunting. Looks as if it could also have been a converted flintlock by the old spring on the side of the lock and what looks like the remains of the old flash pan below the nipple drum.