"Mizter T" gurgled happily, sounding much like they
were saying:

Not so fast Mr Perry! ITYF there are many examples of where route
specific branding has been used on buses around the country - so it's
not really an edge case. No current examples from London readily spring
to mind, but a number of Routemaster operated routes (e.g. 12, 36, 18,
73) used to go in for it (from the 90's onwards I think, i.e. post split
up and privatisation of the LT buses operation) as did some other
routes.

Do I recall the RV1 riverside route using fairly heavily branded buses?