I thought I had discovered a similar example the other day. In his Whimpering in the Rhododendrons - a lighthearted social history of the English prep school - Arthur Marshall recalled that:
Another headmaster had a rich voice with a trace of a Yorkshire accent and was unable to pronounce the letter "r", the boys naturally looking keenly forward to the Passiontide lesson in Chapel, "... and Bawabbas was a wobber".I wondered if the Monty Python people had read Marshall's book before writing The Life of Brian. Probably not, given that the film came out in 1979 and the book was published in 1982. So it is just a coincidence.
Another headmaster Marshall mentions was in the habit of beginning prayers with: "Dear Lord, doubtless Thou knowest that in the Daily Telegraph this morning..."