Many thanks SNS3Guppy for your long and detailed posting.
I certainly wasn't aware about the majority of what you have mentioned.
With the Air Canada Flight 797 incident, 23 out of the 41 passengers and crew died. As I mentioned on one of my earlier threads, the ACI episode mentions that the coroner's report stated many (if not all) of the deceased had extreme levels of CO3 and other noxious gasses in their bloodstreams. So it's reasonable to assume that some, if not many of the deceased may have been dead prior to landing and were therefore not killed by the fire itself.
I was left with the impression that, had the flight needed to continue for another 5 or 10 minutes, none of the passengers nor cabin crew may have survived. So imagine the disbelief of the PIC and F/O upon making a safe landing if this had eventuated.
Your post has certainly explained well why oxygen masks are not deployed in the cabin in the event of fire, and how useless they'd be if they were. And in this sense, it seems that things are not a lot different in 1983 compared to 2009. I guess it then begs the question, if the equipment/technology is available (as in what is used in the cockpit), then why aren't they used in the cabin area?
The obvious answer is cost. Perhaps $5-10K per mask, including all fittings etc, so may well be in the 7 figures for an entire aircraft (say a 737 or Airbus A320). Unless there's any other logical reasons.
As you've mentioned, inflight fires are very rare. The ACI episode, and internet websites, mention several areas of improvements that were made as a result of the flight 797 incident. They mentioned changes to the materials that were used as aircraft furnishings; lights in the aisle that indicated the exit; installing smoke detectors in all toilets; and improved firefighting training and equipment to crew. (Amongst other things).
I guess the fact that, over most (or all?) of the world, smoking has been gradually phased out in all passenger aircraft over the past 25 years - which I would have to take it would have lessened the likelihood of cabin fires in this time.