In first grade, Catholic school, we had to practice writing our initials over and over again on that blue lined paper. Well, my initials are DO, so the entire page was DO DO DO…
Fellow students started teasing me “Doo Doo, Doo, Doo” etc. Well, sister Mary Jerome (yes I remember her name) came over and said, “Don, your last name has a capital O and a capital C (Irish name O’C), you can sign your initials DOC.” I’ve been signing my initials as DOC ever since and have been known as Doc since then. If ya zoom in on the Primo build above and look at the headstock, there it is.