Gatwick or Redhill?
Re G-AFYH #21 and OO-FAH #25 , I would say its the same Halifax by the petrol pumps (theres another one in #25) and Gatwick seems more likely..... shape of hangar, a Halifax could land at Redhill but could it get out? Interesting photos!
At one point (late 40s?) Transocean DC-4s were freighting in Bonanzas from the USA on the 'empty' leg of emigrant flights to Canada (UK Govt scheme)...maybe included the Swiss one