Yes that is a working phone. It was nailed up along a lonesome road on Stewart Island, New Zealand. I visited NZ after my stint in Antarctica in 1997. It was great: beautiful, friendly, and easy to get around. I’d love to go back. Here’s what I wrote about Stewart Island:

“Feb. 26, 1997. Spent the night in Invercargill after a lovely train ride from Dunedin. The train passed by farms full of sheep, horse, cows, etc. When the train approached a group of sheep would dart away from the tracks causing all the other animals to follow suit……After a 20min. plane ride in what felt like a cardboard box with wings I am on Stewart Is. There are beautiful beaches and a real sense of an island community. Things are changing fast here, I wonder how long it will stay this way. Went for a hike and saw wild parakeets and other native birds but no Kiwis.”