Long shot but was he the son of Gp Cpt Green of WWII? The CO at Swinderby in '74 when I did my square bashing was the same Gp Cpt Green (who was a top bloke). He had a son who was at the time a new flying recruit on Bulldogs I seem to remember.
In '74 Bill Green had just left Cranwell following a tour as a JP QFI so I don't think this would be the same man.
YS