I saw it at least twice, once at the Air Tattoo at Greenham Common in 1976, and again flying over my school a year or so later - the Bursar was walking past at the time and did a classic double take - an aeroplane flying backwards! Possibly also at Farnborough if it attended from 1978 onwards.
I see its first flight was at Wisley and the original registered address for David Lockspeiser was in Shalford both of which weren't far from the school (as was Dunsfold), though I never saw the aircraft flying on any other occasion or at any of the Surrey/Sussex airfields I visited in the late 1970s.