NJ; Yes, I think you are right on that.
But on the rhyming slang you have missed out the beginning;
In a performance I saw at The Royal Court in the early 60's called 'Brecht on Brecht' - a collection of Brecht's sketches. I still remember,
"Why are you always climbing up Mr Smith's plaster?"
"Plaster?"
"Plaster - Paris, - Paris - Arris, Arris - Aristotle, - Aristotle - Bottle, Bottle - Bottle and Glass, - up his ....!"