I should have mentioned , mechanic is local Nissan dealership at Wongan Hills (Jolly and Sons) ...
Am looking at Engineexchange - $6500 for recond with 12 month warranty - pretty sure the conditions will be new pump-turbo-radiator which doubles the price - then labour (already up for $1K at Jollys ...
Looked at Brunswick Diesels , even though I'm not a big fan of these