And why is that?  Some of the results weren't even known to the people
who did the study.

No, "many" people did not.  A few did.  And not as many, in
proportion, as today, when the over-85 age group is the fastest-
growing demographic.

Exercise and diet and limited exposure to industrial dusts would all
be relevant.

Sure, "why" is important, but first you have to find out the facts,
so you know what it is you're trying to explain.

 -- David Wright :: alphabeta at prodigy.net
    These are my opinions only, but they're almost always correct.
    "If you can't say something nice, then sit next to me."
                                -- Alice Roosevelt Longworth

This much after the fact it's pretty near impossible to find out
how it was that someone a long time ago beat the odds.

There are, after all, plentiful counterexamples of people who
violated just about every one of your suggestions and ended up
living very long lives.  Alcohol?  Cigarettes?  Some of the worst
air pollution on the planet?  Constant exposure to scores of
total strangers?  Rich food?

Try the Queen of England's mother.

About all she *didn't* violate on your list was attitude -- and
the books are full of people living past the century mark with
dispositions that would make Scrooge look sunny.