I remember being told when i was in highschool, it was always pronounced "pell mell" Is this still true?

Bill, I have never heard it pronounced anyway but 'Paul Maul' or 'Pal Mal' or simply 'The Mall'.

The Flashman books by George MacDonald Fraser is a very good source for Victorian history and even the pronunciation of words at the time. Mr. Fraser is meticulous with his reseach.