That is another fascinating find from the European glaciers. I have not tried the bowcase yet, but would love to some day. I do wonder about the white side of the bark being out on the replica, most of the NA birch bark items have the red side out. Looks like the drawing shows two layers of mark, the inside layer being red out and the outside being white out. They sure didn't want that bow to get wet did they?
Keep us posted if you work on a replica.
Kyle