Jack,
I have lots of maple burl. It is one of my "go to" choices, when it comes to building a Randall knife. Your Bowie doesn't seem to have all of the characteristics of a maple. There are no burls, for one thing. In the 70's the Randall shop had a decent amount of walnut, figured just like your Bowie. Although it certainly could be something else, I still believe it is exhibition-grade walnut. Whatever the outcome, it's a nice piece.
Best, Capt. Chris