Wrathmonk, the '73 redundancies were well targetted. Can't remember all the criteria but I seem to recall that Canberra crew were in the bracket and the FJ guys were excluded. Sqn Ldr and above could volunteer but there were shed loads of compulsory ones too, even guys promoted into the bracket.
In the 92 round there were lots of wholesale redundancies, SimTech for one, the whole trade went.