[marty in Ohio]

Back in the '60's they flew tri-motors to the islands in western Lake Erie. My wife and I, before we were married, went to Put-in-Bay and took along her 15 year old brother. It was the first time he had ever flown. We came back on the last flight of the day and found that the plane was over booked. They told me that if I could wait they would send over a Cessna to fly me back, or if someone was willing to sit in the co-pilot seat we could all go together. Well, brother rode up front. What an experience!! He said he couldn't hear the pilot during the flight as he left the windows in the cockpit open. This was so the pilot could see the gauges on the outboard engines. On this plane the outside skin was the same as the inside skin. The seats were long benches along the sides.
Island Airlines, known as the shortest airline in the world, had several tri-motors and used many of them for spare parts. They no longer use them and I don't know if any still exist.
Bygone days are sometimes the best.