Having first-hand experience of using the original UK Phone Booth shown in the photos, I can tell you how good they were while they were maintained. Their heyday was decades before mobile phones. The red phone booth was designed by architect. It's made of cast iron with small windows, the walls don't resonate and conduct outside noise. The door is very heavy. As soon as the door closes, almost all of outside noise stops and inside it became a safe haven from outside.  Inside there were paper phone book directories , a writng surface and even a mirror and a room light. There was even a three-digit number you could call to hear playing the top ten chart singles through the telephone and the music was clear, we used to pass the receiver between us to take turns to listen. Can't do that over GSM with its aggressive digital compression that has now reduced mobile voice communication to just spoken words.... "What? Say again, you're breaking up", "Hello?"  "No Honey!, we're not breaking up") . 

Nice idea! Did you finally managed to procure a booth?
I am working on European video exchange project ( https://hackaday.io/project/27790-window-on-the-world ) and I think those booth would be an interesting form factor to work with.