(1962, Michael Craig, Patrick McGoohan, Janet Munro)

Filmed partly in Seaham, County Durham, also in the city of Durham.
This passing double decker is Northern General 1708, (CUB708) a 1956 Guy Arab IV/Park Royal:

In a dramatic scene towards the end of the film, two vehicles pass, firstly SWT236, a 1956 Bedford SBG with Yeates body. This was new to Anderton of Keighley, but I can't vouch for the owner in this view:

Secondly we see Northern General 1525 (CU6325), a 1954 Weymann bodied Guy Arab IV: