I have a savage arms 20ga pump action shotgun that was given to me after my Grandfather died. I'm told he had it before my father was born (1950), and we have good reason to believe it's pre-WWII. It's still in great working condition, and I still use it for trap, skeet, and sporting clays.
I have an old Springfield double barrel 12 gauge that belonged to my grandfather. It was made sometime in the 40s.
My next oldest is my Seecamp, it's a special edition that was made in 1985 sometime.
My SIG P226 was made in 1986.