MX5_Boy, I admire your love of AN but on this I think you are wrong.
The A320 is the most flexible member of the AN fleet. It can cover everyone of AN's domestic routes, has low operating costs, is liked by pax and is the youngest member as well.
I loved travelling on the 762s but unfortunately they don't have a future in AN. They are old and have an unfortunate recent history which is a pax turn-off whether this is justified or not.
Realistically there are only 2 options for AN at this point, Fox/Lew or liquidation. Under either option the 767s are on their way out so the administrators are probably correct in keeping them parked.
Seeing them sitting alone at MEL and SYD is sad but unfortunately their time has come.
As far as your rumour that they are still owned by AN, I have a feeling this might be true. NZ were in the process of selling them to GECAS but it appears this may not have been completed before AN collapsed. The only positive of this is that the 762s can now be sold (for a very reduced amount) by the administrators for the benefit of AN creditors rather than the benefit of the NZ bank account.