Brian - it's getting off-topic, but this is fascinating stuff for me. Coming to this cold, it had never occurred to me that what PB was doing on that song was basically a I/IV/V job with added melody. I briefly tried to duplicate what his accompaniment sounded like on EC; I ended up with relative minors & added passing chords all over the place, & it still didn't sound nearly busy enough.

Time to stop trying to follow what a gifted but eccentric player of a different instrument came up with, I guess, & start from scratch. Although, in the case of that song, scratch is a rather forbidding place, given that the whole first line (which in up/down notation goes *UUDUUDDDUUUDDD) is on one chord.