I remember the Beech 200 at Denham (or one of them at least); I used to watch it going in and out of the blister hangar, nosing in and reversing out!!
I think they managed to acquire a UHF radio for operations in/out of military airfields and I sometimes spoke to them on it when they used Farnborough.
GALWC, the Hunting Surveys Dakota based at White Waltham, also had a UHF radio.