Many ex RAF pilots flew with the RAAF during the Vietnam conflict on both the Caribou and the Canberra
OAC,
2 SQN Canberras - no ex RAF pilots or navs. There was one ex RAF Regt chap as OiC airfield defence guards.
Of interest, one CO 2 SQN had served an exchange with the RAF on 74 and 92 SQNS (Hunters, I guess).
35 SQN Caribou - unsure, possible but none spring to mind.
9 SQN Iroquois - yes, "Lofty" Lance (#18, #37) was killed in action; there may have been other ex-RAF pilots on choppers.