An interesting, complex design built by college students in the 1920's. A friend of mine purchased the rights to this pen and ask me to turn a few proto-type replicas (sample pictures below) which I did. I used my limited skills at that time and would do things a bit differently now. I have trouble understanding just how technology back then allowed the skilled individual to complete such feats they were able to accomplish. The little rolling wheel at the top of these pens is complicated to say the least. My guess is that it was a screw machine application.
Chance a glance and comment if you wish.