Got an idea just now that might sell a few copies: Monty Python Annotated for Americans, containing answers to such questions as “What dialect is Palin doing in this bit?”
This thought was prompted by watching My Fair Lady. In the first scene where Higgins shows his phonetic jottings to Eliza, I obviously had to pause, and found that I could read it no better than she could; most of the characters look like International Phonetic Alphabet, but if so they’re a nonsensical jumble – and what’s the alveolar click doing in Covent Garden? “Ha!” my housemate snorts. “They couldn’t find anyone who could put together the real thing?” They rarely do, of course, but this was a major production. . . Later I learn that it’s not IPA but an older scheme, the Visible Speech of A.M.Bell.