I am kind of thinking I agree with Dennis. For a Appalachian rifle, walnut sure does look nice, especially stained dark.
That said, my friend once wisely told me, "When someone says a stock is beautiful, what are they referring to? The wood. Buy the best wood you can." I think if I was going maple, I'd buy a really pretty piece. SMRs often had no carving, so the curl will not fight visually with the carving.
Just thinking out loud. God Bless, Marc