Jayviator,
When ZA449 was a GR1 it spent some time in the flight test world. We had it at Boscombe Down on 'A' Squadron/Fixed Wing Test Squadron and I first flew it there on 27 August 1987 and last flew it there on 17 May 1990. We used it for training, supporting some missile tracking system trials as a target and for RHWR trials. I also flew a sortie looking to expand the crosswind landing envelope of some of the degraded CSAS modes, a 3-tank handling sortie plus a sortie as a receiver during the Tristar tanker development trials. I don't think that there was ever any flight test instrumentation fitted so we must just have used on-board observations plus data from the ADR.
I also flew it when I was on Experimental Flying Squadron at Farnborough, the first sortie being on 6 December 1993 and the last 26 January 1994. We used it for training flying and again as a target supporting other trials including a helmet mounted sight trial in a Jaguar. EFS moved to Boscombe Down in April 1994 when military flying at Farnborough ceased. I flew 449 again at Boscombe on 5 December 1994 on a sortie to clear a fixed FLIR pod on station 5. I think that it may then have been on the strength of the SAOEU as this was their trial as a pre-cursor to the GR4 entering service but it was initially a joint trial with EFS.
Happy memories!