When Jasper Carrott was playing clubs in the early seventies he always played this, and always claimed to have written it himself. He could get away with it because Fred Wedlock was a full-time college lecturer at the time, and never played very far from his Bristol home. This irritated some people I knew to the extent that they produced the Fred Wedlock recording at a Jasper Carrott gig, pointed out the songwriting credit (Simon/Wedlock), and asked him to explain.
He caved in, admitted he didn't write it, and remembered an urgent appointment!