Here's an oddball sidetrack for those who remember the somewhat strange looking custom-built road coaches that BEA used from Heathrow to Central London, a fleet of 65 in all. They were owned by BEA but operated for them under contract by London Transport. They came along in 1953 and lasted until 1966, so all through the period being discussed here, and I get the feeling that several will recall them. I do from the end of their time.
IAN'S BUS STOP: The LONDON TRANSPORT RFs
One of their features was they had on the front indications of destination, able to be wound round like any other bus, but the points listed were all the BEA destinations, as they were operated one bus per specific flight rather than a general purpose regular service. You checked in at the town terminal, and your baggage travelled with you in the very large underfloor compartment of your bus. So you would see buses to "Milan" or "Stockholm" headed down Cromwell Road in Kensington alongside the regular 74 to Putney ! As the passengers were seated very high up they could look down, appropriately haughtily no doubt, on the hoi polloi on the pavement below.
It was only when reading the article I realised they always had semaphore direction indicators (well, normal for road vehicles in 1953 I suppose) which must have been more than a bit anachronistic once the M4 opened !