My aunt was the operator. My mother worked at the bank; her number was 9. Ours was 370J. When we finally got a private line they dropped the J.
I can remember picking up the phone and saying "number nine please" and Aunt Mary said "Donny, your mom isn't there, she is at the post office." Incidentally the post office number was 1.
I'm still "Donny" in Oklahoma.