Thanks Geoff.
The two Devons involved, NZ 1823 and NZ1825 had flown very little in New Zealand.
After delivery in 1953 they were then stored as attrittion airframes.
In August 1966 they were removed from storage and transported to de Havilland New Zealand where they were completely overhauled and updated prior to moving to Malaysia in early 1968.
I believe that they were repainted into RMAF colours in New Zealand and possibly even test-flown in RMAF livery at that time.
In any event, they would still have been fairly low-time aircraft by 1975.
As I have been unable to track them any further past that date, I agree that they were most likely scrapped at end of their military service.
Possibly, given that they were gift aircraft, there was some form of agreement that they would not be on-sold once they had become surplus?