In my TL the RAN would still get the Centaur and have a stronger FAA, the FAA was one of the mistakes of the ADF. Also the RAAF lost 19 of the 116 Mirages to crashes between 1964 and 1973 when the Phantoms were handed back, and kept 10 Canberras on strength until 1982 so the RAAF would keep the 23 Phantoms instead of handing them back upon the celivery of the F111.