From the LA Forum, 27 June, 1977, after "No Quarter":
"John Paul Jones has finally got that strawberry tart out of his pocket, and he also got it out of his hair...and he woke up with a half-tin of sardines by his nose, so I guess he had a pretty pleasant sleep last night. And so it is a great pleasure that we introduce him with his three-necked instrument, which is why we're so ENVIOUS of him. (And the same to you.) For a man who's always stayed in the background, he's been getting a lot of strawberry pie!"
First time I heard that, I was like, "What did he just say?!" Throughout the first set of the show, Plant keeps making reference to John Paul Jones and strawberry tarts...suddenly it all makes sense, and what he says is pretty smutty if you stop and think about it. Of course, judging from all the numerous references made over the years, maybe Percy just had a thing about...ahem...cunnilingus...the "Oh, Georgina" section of "IMTOD" from 19 March '75 makes that pretty clear.
(mind you, I've got a bit of a taste for strawberry pie meself...)