That is a very good fix of the lobbing sight recess and while the walnut and maple are different there is every reason to have used it for the continuity of the historical use it has been put to.
Is it a trick of the light or do I see a comb flute on the left of the stock but I dont see one on the right. I wondered if you were left handed.
Yhere is something fundamentally satisfying in taking a slab of wood and whittling a stock out of it and when it is done so nicely it is also a treat for those of us who like to see them.