Hazy recollection here. "Wasn't there a tunnel from Central to the cargocentre, not for public though" Does anyone remember the maps, published by one of the fuel companies, 1/6d if I remember correctly with a big map of LHR ( LAP) in the middle and colour pictures of aircraft around the edge. Amazing how many comets Aerolineas Argentinas, BEA, BOAC Olympic, Sudan, MSA, MEA, Kuwait and Egyptair/UAA included there are round it.
Thanks for the thread,
Be lucky
David