Found this photo looking up my more normal steam power; this is on the zoo railroad in Omaha, Neb. No doubt as to the originating influence!
http://commons.wikimedia.org/wiki/File:Virgielocomotive0533.jpg
The Minitrains line is back in production; that would likely be the base for someone wanting to tackle this.
http://www.lehightonhobbies.com/minitrains.htm