Found this beauty in Sand Springs, OK, on the Sand Springs Ry. It's a former Frisco side-door caboose. My guess is that it was used on certain locals and mixed trains on the Frisco system.
Reminds me of Rock Island outside braced versions. But those were wood sided. This looks to be all steel. Boxcab E50
My Mom must have ridden in something like that between Hugo and Ardmore during WWII. She said it was like a long caboose with passenger seats and a baggage door. It was mid summer with no air conditioning. As an Army Nurse, she was in full uniform and was very uncomfortable to say the least.
