I collected a number of different ones of these...as I favor postal cars and mail
trains.... Kris cars, made by Kristofferson? from old KMT-AMT molds...made
several that were inexpensive (haven't shopped for them lately). The original
AMT/KMT versions have cast couplers, so I would go with the Kris versions with
Lionel compatible knuckles. There have been a number made by various mfrs.,
so they are common, BUT probably not in your location. Williams for years offered
several variations of REA cars, I think from these same molds, before the Bachmann
acquisition...and maybe still does. If you had asked your question before York,
probably a number of us would have spotted some on our rounds.