These models came out circa 1980 as part of Bachmann's "Old West" series. As of this 2016 writing, they are only available as part of Bachmann trainsets (IE not sold separately). I'm told that this is actually a fairly close model of a D&RG Class 1 narrow gauge caboose.
Trivia - Panamint Models (Shapeways) sells replacement underframes for these models. They are available with either conventional passenger car steps or cast-steel tender style steps. Based on Pennsylvania, Central Pacific, NYC, Ma&Pa and NYO&W cars that entered service around 1875 and lasted into the 1930's.
