These models were initially imported by Revell (starting in the late 60s) and later on by Walthers. The former were packaged "Revell-Rapido" boxes, whereas the latter were packaged in Arnold's familiar orange and white boxes. Arnold was acquired by Rivarossi in the 1990s and this model was ultimately discontinued circa 2006 when Rivarossi went bankrupt and was liquidated.
The wheels are plastic and the couplers are truck-mounted Rapidos. They are stamped "Arnold Rapido, Made in W. Germany" on the bottom.
I'm told that the prototype for this model is a Union Pacific NCS (Non Common Standard) caboose made in the late 19th century (just with numerous prototypical inaccuracies).
