I was a member of the RAF Thornhill, 5 FTS (Rhodesia) gliding club back in 1952-53. We had a “Primary,” probably the most elementary form of flying machine then still flying; I’m sure the Wright Brothers would feel very much at home with it. Initial flights were flown in this "Primary" before eventually graduating to a "Tutor".
The tow truck was fuelled by high-octane fuel "milked" from the station's Harvards - so purloining fuel for leisure purposes, albeit for a sanctioned leisure activity goes back to 1952 at least.
My first six-foot above the ground flight in the "Primary" as it was dragged across the airfield by the tow-truck.
Mind you the club still charged 1/- (5p) for each launch, probably charged to repair the tow-truck's engine valve-seals which didn't agree with aviation high octane fuel!
WT