(1971, John Alderton, Derek Guyler)

Jaunty film spinoff from the TV series opens with teacher Mr Hedges (Alderton) catching a London Transport AEC Routemaster on service 8 to get to school. He and his class go on a school trip - transport is provided by two Harrington Cavalier bodied AEC Reliances of Jack Crump, BMK341A and GMV514B:

BMK's driver is played by Jack Smethurst, seen not quite running down caretaker Mr Potter (Derrick Guyler)

The Fenn Street School kids get to travel on BMK341A:

(thanks Adam Floyd and Jon Price)