There are car people who like a little bit of everything, and there are car people who are specific about what they like. Billy Watson is a Mustang guy, plain and simple. Even more specifically, Billy Watson is a first-generation-Mustang guy. He repairs and restores exclusively 1964½–73 Mustangs.
This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2018/12/12/the-pony-pen