You clearly know much about these matters, Rick.
I've been retired many years and was on a final-salary scheme when I
was working.
My pension is index-linked. I've not noticed any mention of
index-linking when these matters are discussed here. Is I/L implicit in a
F/S scheme, or am I just fortunate?

I don't think it's implicit, but I do believe it's almost universal - but
then I don't know the terms and conditions of all the schemes there are.

Sadly, my wife dumped me some years ago but my scheme would have given
my widow a 'half-pension' for her remaining years. Is that common with
these schemes?

Yes, it is common. But in some cases it's taken time for this to apply,
particularly for different sexes. For example, until sometime in the 80s
(can't remember when), pensions for male teachers included a 50% widow's
pension on death. But this was not true in reverse, i.e. if a female teacher
died her husband did not get a widower's pension - although the wife could
pay into the scheme to establish this entitlement. But then later the
entitlement became equal (due to the Sexual Relations Act, I suppose).

Rob