After a friend brought over cartons of partially built kits, I found this Vanderbilt tender that I think was meant to accompany a partially constructed brass-kit for a Big Boy or other giant articulated locomotive. The nicest parts of this enormous tender are the articulated 6-wheel trucks and the nicely made hand rails. I suspected that this model, which is solid metal, was a Bowser kit.
When I put the tender on eBay in June 2005, one member told me that it was "a 16,000 gallon tender for many Southern Pacific engines," and another reported that it was in fact "a Bowser SP-1 tender." Although the unknown modeler who was the ultimate source of the tender apparently planned to use it with a large articulated locomotive, I have since seen it only with other kinds of SP locomotives. Having mentioned eBay, I should add that, acting once again as the representative of Augustus Melmotte, I sent it on its way to a railroad in North Carolina in exchange for some hard cash.