Thank you for your kind answer . Both from you and werewolf255. > These index wheels were mass produced, and I still don't know how they did it. Fascinating.

Thank you for your kind answer . Both from you and werewolf255. > These index wheels were mass produced, and I still don't know how they did it. Fascinating. My guess would be some form of etching process. But that would make it some form of MEMS years before the first commonly recognised MEMS components.