I think I still have several of the minifigs you can see around the 1975 time frame. We used to have at least one or two of the one from 1974, but I don't know if that's still around my house.

"Happy 40th Birthday, LEGO Minifigure! - GeekDad"

https://geekdad.com/2018/08/happy-40th-birthday-lego-minifigure/