I seem to recall the 601P Chuckie used to fly had been modified with dual turbos? I was in Port Morbid on one occasion and RT invited me to have a look-see at his pride and joy - which had suffered a turbo failure.
I think the engineers had to pull the engine to change a turbo?
Flew with RT a few times. In my younger days I often lived dangerously!
He went through a hail storm at Mackay (?), took out the windscreen and both pilots ended up in hospital with facial lacerations!