Dave,
It wont help you quest much , but about 1993/4 I had nearly a dozen Griffon 58 engines and associated paperwork/cards, I am nearly certain that 3 had the 972 tail number on the cards as being one time power suppliers to that airframe, I will carry on looking ....but dont hold ya breath.
Most of the Griffons I had went to the Pylon racers in the US, a fitting end to a superb piece of kit!
PeterR-B
Lancashire