I was a secretary in the 70's. The IBM Selectric had two font selections: Courier 10 and Elite 12. I think there were still a LOT of companies still using manuals. IBM also had another typewriter that had proportional spacing. I don't remember what year I used that one, but I remember that a small "i" counted for 1, and a capital W counted for 5. It was a BEAR to do columns, margins and the like. Had to count everything!! Sometime before 78 the law firm I was working for tried the newfangled Savin word processor. I don't remember what the fonts were on that one because I didn't like it and wouldn't use it. (How far I've come!!)
Please see 198 for your professional input.
Selectric Composer. Linked to earlier in this thread.