In Oct 1991, the long-established rank of Cadet Pilot was abolished and replaced by Offficer Cadet (Pilot). Before then it was easy - those already selected for the RAF were Acting Pilot Officers (and paid as such), the rest were Cadet Pilots.
As an APO in 1972 I received about £1200 per year. To give you an idea how far that went, accommodation ('hall fees') were £6 per week, a fixed price lunch with waiter service in the Chinese restaurant opposite the hall was about 35p and an 18 month old MG Midget cost me £750.
There were no'bursars' in those days, that was another cheapskate scheme brought in later on. And it's worth what - about £1000 per annum? That's about 8% of what I was paid.
As has already been said, Grand Fromage, flight instruction will only count towards civil licences if conducted by a current CFS-catted QFI on type or a civilian pilot with a valid FI Rating. Anything else will be considered to be passenger flying.