I think that it was XR 222. When I was learning to fly Cessna 150s at the Bedfordshire Air Centre in 1968, we students used to nip off to the College hangar to have a look at the treasures therein. The biggest and best was the TSR2, but there were all sorts of other very interesting items in the hangar!
Wilson, Healey and Brown weren't the chief murderers. You can blame the late Earl Mountbottom for killing off the aircraft's export potential........