Nick W - I think I got the verbal reasoning part wrong. That was another kind of exam, but taken around the same time.
The kids took mock exams for which scores were published and gave the school an idea of who might pass or not, and allowed them to be categorised as A, B etc. by the Headmaster, who could then make his recommendations. This was not common knowledge, but those who thought they needed to know, knew how it worked and worked the system accordingly.
Being very active in the PTA or also being a teacher in another school and helping in this school when it was needed, was the sort of thing that could swing things in someones favour. When they took the real thing, I dont recall if the marks for the real exam were disclosed to parents or not, but I do know the Headmaster, under some pressure, admitted how the system worked, after it was all over and done.
It was the last year of that system, so he probably thought it didnt matter too much.