So, then, hopefully in conclusion, Triumph ostensibly did retroactively change the service interval for all RIIIs, including the older models to once every 20,000 miles? That's the question, fellas'.
It is somewhat a moot issue for me - not of great concern - because the Carpenterization of my ride included under valve shims, titanium valve somethings or other, etc., and some other internal goodies that should hold up quite a while provided that I keep the motor properly tuned and continue using the correct type(s) of motor oil for my worked motor, changed at proper intervals.