A super memory. There are photos of Castle Don. in 1965 on the internet somewhere, maybe on a BBC site, posted in conjunction with the 50th anniversary.
'HY was the third of the fleet, I seem to recall.
A certain Captain B., notable maverick and long-serving Midland aviator, beat up the BMA admin block one day in an Argonaut, (according to my sister who worked there), causing several staff to dive under their desks for cover.