French musket

[JamesKelly]

Not ready to take the barrel out.
The lock recess looks like this was the original lock used. That is, the recess has not been recut.
There is a stamp on the inside of the lockplate. So far this is the only mark I have found on this musket.

I realize it does not match any standard French musket from Model 1717 on. 1717 was when the French more or less standardized their musket patterns.

Part octagon, part round barrels like on this musket were used on earlier guns.

My thought is that it was made some time between 1680 and 1720.

Well, any thoughts on what this lock mark might be?