I'm with you on the used guns. I really like older 870's better than new ones.
My favorite is my '91 police trainer that was well-used. The outside looked better than the ol' '55 but the hammer was actually peened, badly, from usage.
It was a pre-Express though with no mag dimples and polished metal under blue.
This gun wears a 20" rifle-sighted barrel and is my primary everything gun. I am trying to phase it out of clay shooting and learn to shoot this "new" 28" plain-barreled '55 but it is a hard gun to put down for long.
Good luck with yours.
Mike