There's a museum full of this stuff near the airport.
https://www.telcomhistory.org/connections-museum-seattle/

My son and I spent a fascinating morning there recently (of course, it's closed now, due to coronavirus). Very hands on and it's run as a tour with a guide who answers questions, demos the equipment and lets you try your hand. If you're an obsolete technology geek, it's well worth the visit.

I was a telephone operator for Bell South in the mid '70s. I was straight out of high school and it was a good job. The switchboards were exactly the same as these except we had modern headpieces that looped over one ear and a skinny plastic mouthpiece. It was not nearly as complicated as it looks and I could work two switchboards at once. Then a couple of years later, the phone company switched over to their new computer terminals. I HATED the new terminals and soon quit. I enjoyed the old style switchboards much more. Little did we all know how soon the operator job would become all but obsolete with advances in technology. So I'm glad I moved on to a job in an industry that is always needed.

NumBA paalleezze?

In 1968, the night manager at the Cove Inn in Naples, Florida, had the insane idea of having me handle the switchboard while he ran an errand. I was a newbie bellhop and he gave me no instruction at all.

I freaked when I saw that contraption and tried to handle a couple of calls when the lights blinked, but decided the only rational thing to do was nothing.

So that's what I did until he returned.

These women are switching phone connections, now done by something you can't see without a microscope (unpackaged IC) and switching more calls in a second then could be done using the method in the photo in many lifetimes.

Here at the phone company, we serve everyone from presidents and kings, right on down to the scum of the earth.