I was born and raised in Bovingdon (my parents still live in the same house there), I can remember late 80's watching the farmer wheel out his plane from an open fronted barn (A bi plane of some sort IIRC). I can also remember a Windsock being on the field - this was both before the prison was built (Against my parents wisdom the old control tower was a cool area to explore) and also not long after it was built. If I remember correctly the farmer back then used the grass rather than the concrete.
If you are new to the area the village itself is not that big and everyone knows everyone pretty much; so speaking with some of the locals. e.g. Gilbert Motors probably would be a good bet (On Ley Hill road on the left before the aston garage) Steve Gilbert runs the business that was previously his dads and I know his son is a PPL holder. Gilberts have been there 40+ years and will know the local community and what has been going on around the airfield. Probably best to pop in for a chat (ask for steve) as they are usually very busy and dont use the phone more than they have to.
PM me if you want more names, in the meantime I will ask around, I have a friend who has family in whelply hill who may have some recollections.