If "longest-lived" means durability, I don't think production year is the relevant criteria. I put nearly 20k rounds through my 6 year old 686 this year alone, and my best guess is it's shot around 70k rounds to date, yet my 686 is holding up fine, and likely has multiples of 70k left in it. I'd bet the great majority of older blued revolvers have seen a very small fraction of this.
As far as DA revolver durability, my bet would be on the Manurhin, with Rugers and S&Ws honorable mentions. In SA revos, Freedom Arms likely takes it, with Ruger making a fine showing.