I have one of these cars and was wondering if it ever had a prototype and what years this type (style??) car is accurate for? It's a neat car and i would like to use it on a modern era layout but have no idea what years it is accurate for or if any are still around and in service today.
Here is a pic of mine that I modified with Athearn Buckeye trucks. Having seen enough guys have trouble keepin' 'em on the rail with all those wheels, I did this mod to give the car a different appearance and make her easier to keep on the tracks. The Buckeyes work great!! http://www.railroadforum.com/upload/tankertoad70/WECX101.4.jpg
The article in the October RMC is actually about detailing a Walthers two-truck depressed center car (Soo Line prototype from the 1960's or 1970's).
The four-truck "heavy duty" flatcar that both Athearn and MDC Roundhouse originally made in cast metal before Athearn did the same car in styrene, dates back to the 1950's, at least. The D&H had several of them, mainly to carry heavy General Electric equipment from Schenectady, NY. At least one was in use at least as recently as a couple of years ago, because I found one at the Port of Albany carrying heavy electric generating equipment destined for Vietnam!