From the summer of 1947 till Nov '49 I worked as a met asistant in the Met Office which was just west of the original control tower. I lived in Hayes and cycled to work through Harlington. The entrance to the airport was from the Bath Road so that would put the tower roughly where the entrance to the tunnel is now. The Three Magpies was on the Bath Road just west of the entrance. (Not shown on the map at the beginning)
There was a canteen which we walked to across the apron. No high vis jackets then! I remember AOA and /or PAA Stratocruisers and Constellations. O P Jones came in for briefings. He was easily recognisable but was just one of a long list of "gods" to a sixteen year old.
My first flight into LAP was in a Lancashire Airways Rapide from Bovingdon in 1949 where I was on a temporary attachment. They flew over frequently to give joyrides from just outside the public viewing area which was west of the Met Office. A female pilot was employed by them which seemed unusual to me. Even then I was a sexist pig. Also the GCA controller's patter was broadcast over the Tannoy in the public viewing area.
In Nov '49 I was called up for national service, trained as a pilot and for the next 42 years was paid to enjoy myself first by the King, then the Queen and eventually various airlines. Much better than working for a living.