Forgive me, I've been disappearing down rabbit holes over the last few days so here are a couple of small references that I find interesting.
From the doc, we know Henley saw Elton John's first US performance at the Troubadour, but do you know who was the first act that Elton and his band saw at the Troubadour? Yes, that would be Longbranch Pennywhistle opening for The Dillards.
http://www.eltonjohn.com/45-years-ag...the-us-part-1/
Next is an interview with the members of Honey Ltd, earlier known as the Mama Cats, who were one of Punch Andrews' acts in Detroit before moving to LA. (I think it's been posted before because I remember someone identifying which was Joan and which was Alex Silwin). They also sang backup on Ramblin' Gamblin' Man.
http://www.furious.com/perfect/honeyltd.html