In the opening scene, shot in London Waterloo railway station, the film of the locomotive arriving at the platform is flipped left-to-right, as revealed by the mirror-reversed number on the side of the locomotive cab. This was most likely intentional, so that in the next shot the platform is on the same side of the train.
Final film of Audrey White.
Directed by the son of one Prime Minister, Herbert Asquith, The Final Test was the favourite of another, Harold Wilson. (source: Odyssey VHS Release, 1994).