Heard back from MM today. Unfortunately there is no way to date their pipes using the labels. They do all their dating by matching to the old catalogs. They were able to tell me that screw in bits would have been in use from the 1930's-50's. Bone would be older than synthetic. It's not a lot to work with but I hope it's some help to others.
Propose moving this to the "Pipe History" area? <img class="emojione" alt="?" title=":shrug:" src="https://cdn.jsdelivr.net/emojione/assets/png/1f937.png?v=2.2.7"/>