Cheadle Boy: sorry, I don't have a date, as above, all my log books for those years, bar one, have gone west. I just am pretty sure it was 1973, summer or spring-looking at the weather etc, because the "cop" of the aircraft first appears in my 1973 CAM, which I've still got.
I'm a member of TAS now-I give talks to them from time to time, next one on 2nd August.
Also, I know Broadway School very well, tho I didn't go there myself, but my parents' house in the early 1970s was one of those on Kingsway that back onto the school's playing field and today I live just round the corner and walk past the school nearly every day.