almost looks sort of like pine done in a walnut stain
The break in the front of the lock kinda says "cherry" to me. Of course, very hard to determine from the pics and probably equally hard in person.
However, if it is cherry, I advise extreme caution and gentleness in handling. I make some custom items for people from wood that has family heritage significance to them. I have had some 200 year old cherry and quickly learned that it can crumble into dust if you look at it cross-eyed. (almost :wink: ) I now won't work with old cherry unless the client allows me to stabilize first. So, any disassembly on that nice rifle could be disastrous.
BTW, I'm nowhere near as expert as others here but it sure does look like a flint to perc. conversion to me.