Spades: Your Google search did turn up one picture I hadn't found before, an architectural model, but like my other searches, most of the pictures weren't of the actual equipment. Lots of diagrams, so I now know HOW it works, but not much modeling info.
Mu26aeh: Thank you! And if you know the modeler, tell him I like his work. That's beautiful.
RockGp40: I'll have to have at least one tank, so thank you, too. I was wondering if they were all the LPG style, which seems to be the common design in diagrams, so that's what I'll use. Probably not a real long one, though, just a little bigger than the tank car, as my elevator doesn't serve that large an area.