I needed a cheap, point-to-point intercom and went to an army surplus sale, bought two sets of TP6N field telephone.
Early 1950s, my dad worked for a phone company in ND. At the time they transitioned from crank to rotary dial. He saved a few phones from the dump -- two oak wall phones, a Bakelite wall phone, and a Bakelite desk phone (which has a crank where you'd expect to see a dial).
Sometime in the 1990s I resurrected them, connecting them as an interview between the house, shop, and sauna.
My brother has the place now. I should repossess those phones, I could use an intercom between my house, shop, and barn.