ASK21 - Vanguards
WE992....
Small addition/correction to your K.21 unit histories:
ZD643, 644 and 645 were delivered to 645 on 1st July '83 -First entry in my logbook 3rd July '83. IIRC we only had three.
First entry for the Grobs was 21 November 1984. K21's went shortly after. Fairly certain, but not 100%, the K-21's went to West Malling thence I know not where.
As an aside, last entry for wooden in my 6748 is Mk III, XE796 was 7 Oct 1984 - but I remember I wasn't one of the last ones to fly them!.
HTH
DD