Tom - In order to make the scabbard usable, you will need to replace the 3-arrow gripper. Actually I have never seen a scabbard that still had a plyable arrow gripper that could be used. Those scabbard arrow grippers were made from a material that has not kept its flexibility over the past +/- 60 years. The leather caps have a molded gripper that is better but many of them are also too hard to use. The leather is worn on this scabbard, but other than a new arrow gripper, it is still very useful.
The 1930s and early 1940s Grumley bows are self bows. Most of his hunting bows are osage and only have one of his hunting bows made of yew, they are rare. Most of the Grumley target bows that are solid wood are made of yew.
Most laminated Grumley bows are 3-laminations, hickory back, yew core and osage belly. They began to appear in the early 1940s.
Nels made his static tips of the Deerslayer and the Bush Bow using several different wood combinations. Sometimes he used just one wood type, like all yew. Sometimes he used alternating colored woods for contrast, sometimes with just a few laminations and others with many laminations. Sometimes he also alternated the color of the laminations in the handle section to match the alternating colors of the tips. He was truly an artist with his bow making as well as every thing that he made.
I have seen a few of the Brooks repro Grumley bows - they are very nicely made.
Like the 1959 Kodiak, there is nothing quite like an original Grumley. However, unlike the 1959 Kodiak, I don't recommend shooting an original Grumley bow. Although I have shot a few original Grumleys and know others who have too, it is best to do as you have done, and get a nice repro to shoot.