OVERHAUL 

a BTF film , showing the extensive overhauling of the London bus fleet.
London Transport's Aldenham bus depot in Elstree, Hertfordshire was the most comprehensive bus overhaul operation in the world. Opened in 1956, it featured in the Cliff Richard film Summer Holiday. It closed in November 1986 and the buildings were demolished in 1996. I alway thought that the Aldenham depot was much older than 1956.