You say: "JB: NSN is A Hard Day's Night half devoted to Brian Epstein."
Actually, A Hard Day's Night SHOULD have been half devoted to Brian Epstein. Alun Owen wanted to write him into the script; but Brian, trained as a stage rather than a screen actor, was far too camera-shy and was forever trying not to overshadow his boys ~ so Owen had to invent "Norm and Shake" instead.
Trivia: there is a scene in a hotel lobby with somebody in the background who is meant to look like Eppy ~ but when you enlarge and clarify screencaps of that scene, you know it isn't. :)