Dick Gilbert has written an excellent book on the company:-
https://www.amazon.co.uk/Air-Bridge-.../dp/B00TQTK862
His collection on Flickr contains many photos of aircraft and staff from ABC, plus many other outstanding historical shots.
https://flic.kr/p/iy5CPb
Hearing one of the Merchantmen rumble up Amber One above Castle Don. around midnight on the Luton-Glasgow papers, is an abiding memory.