John Haddock was a QFI at Syerston (JPs) when I went through training there - 1968-69. He was a bachelor who enjoyed the single life! Don't know his previous history.
I did fly with one of the pilots who was killed in the other Gnat. He was Flt Lt John(?) Lewis - who had just come from an exchange FAA tour on Sea Vixens. He taught me a lot about the "philosophy" of flying......