As I said earlier on this thread, one of the saddest days in my Life when we heard about VH-RMI.
I was working in the Ansett Aircraft Overhaul Hangar at Essendon at the time, we were doing a complete overhaul on one of its sister Viscounts, after the loss of RMI so many people (experts) from all over came to investigate the Viscount we had in pieces.
I had doubts then as did many others working there that it was the cabin blower that caused the loss of RMI, just they could not find anything else. Very poor design really, there was no fire protection in that area at all.
Nothing really changed after that either, just to make sure the drain plug on the blowers was in the correct place.