For all you guys who want something just a little different for your layout, I saw this last week and took these photos. The batteries died, so I didn’t get more, but I think there are enough detail photos here to build a static model, anyway. The steam engine itself is the same inverted type with Stephenson’s link reverse as the traction drillers used. (I can get photos of the engine on the driller at Portersville if there is interest) I left the photos largish so you can better see details.
http://s397.photobucket.com/albums/pp52/steamnut1917/KeystoneEscavator/ No, I’m not really planning to build one, at least not yet.