Nick, you don't need a death certificate. You just need the authority of his next of kin. My wife, although her mother is alive, we NOK of her paternal GF.
I had left Waddo by that time. I can think of three jobs he might have had. He could have been an Ops Officer, a flight sim instructor, or deputy flight safety if such existed.
Earlier, in the QRA era, we had commissioned officers who would be in Ops during flying ops, SNCO who would also cover night and nonflying times. As Master Aircrew your father may well have undertaken Ops Officer duties. What did they do? Mainly acted as top cover/can carrier for the staff who did the work.
I will ask a friend but knowing his memory . . .