Viscount pressurisation was by three Rootes blowers for the pressure and an air to air heat exchanger in the number three exhaust. Why would anyone heat cabin air in an exhaust still beats me, bug smashers use a shroud around the muffler and Janitrols!!, will say no more
Viscounts had a particular smell in them as did most Pommy aircraft. A mixture of oil, fuel, exhaust amongst other things and vomit. I remember the little bottles of Nil Odor when the contents were liberally sprinkled around.
i was fortunate to be a passenger on nearly all of TAA Viscounts and many a ride in the jump seat. Captain Ivan Neale comes to mind.
As an apprentice I worked on them in dock and line maintenance and I can say they were not designed to be easily maintained.