This model dates to the early days of N scale (late 60's / early 70's). Roco also made a similar (but not quite the same) car for Minitrix / Model Power.
Note that the two sides of the same model are not identical (ala the prototype) -
Also note that due to vagueries in the manufacturing process, the brakewheel may be on the "A" end of one car and the "B" end of another car -
Mechanical reefers like these first started appearing circa 1958. I'm not sure what specific prototype this one professes to model, but I'm told that it's at least close to a PFE R70-11/R70-12 series reefer (built in LA at the Roseville shops in 1960-61). The roof detail and the mechanical door on the side aren't correct, but the R70-11/12 series did have a plug door and diagonal steel braces on each side of the door.