That is the concept, all right. But how do you know that "Jody Grinder" is older? There is also a "Jody" prison song; see "Wake up Dead Man," which was Rounder Record 2013 (1965) and doubtless is now a CD.

By the way, a first-rate disk, the best. I saw a film made in the same location, same songs, at the 1970 World Folk Festival. I believe it was introduced by Pete Seeger in person, although memory may be playing tricks on me.