One of the hallmarks of these guns is relatively plain wood for a similar grade of English gun. I believe John makes reference to this in his posts. The wood figure is definitely a couple of levels below the engraving and metal fitting in these guns. I'm not sure if it was difficult to get nice wood in Japan or if they just didn't consider it important.

Yours is some of the best wood I have seen on these guns.

Attached are a few better pictures of engraving.