Requiescant
You Should Not Go To Them, Let Them Come To You...
PP was probably originally destined to be an album track(for the abandoned, original 'Bona Drag'), in particular the longer early version with the extra verse and the coda. I'm pretty sure the single release is slightly sped up too, to give it that extra bounce.I seem to remember being a bit disappointed with the bit in Autobiography when M seemed to just avoid going into detail on PP. I'd wondered if he didn't want to go into the uncertainty of his backing production team/band at the time. Your background info on this groundbreaking doc helps explain it being avoided.
I can't find the actual interview from the time of the single's release where he talks about 'Johnny Go Home'. It's mentioned in the Mozipedia and there's a quote of him talking about it, but they don't give the source of the interview. It's also claimed that Morrissey had first hand experience of hearing London boys using Palare/Polari, but again there is sadly scant information on how this occurred.