Specially designed exhaust pipe cap

I saw this wonderful old machine in the car park of my favorite plant nursery. It was totally surrounded by terra cotta pots, clingfilmed and on pallets; they had obviously just had a large delivery. Sadly I could not get any closer, or a better angled shot.
McCormick Farmall Model H machines stopped being produced in 1954 after 14 years and 390,000 machines ( isn't Google great). This machine is probably older than me.