In the picture of Comet G-ALYP diverted to LTN in 1952, they caption it 'York Peter'
George Able Love Yoke Peter In full in the British phonetic alphabet. My favorite was Nan, as in George Able Nan Baker Easy. Only the Brits could have come up with that. It all went away in March 1956.
Hatfield had a concrete runway from the late 1940s - if I can find the right book I put the date on here.
Many pictures as you say that I haven't seen before and quite accurate for the press.