Heritage Sq. "Tom Thumb" and Hal Wilmunder *LINK*

I'm in the process of researching and finishing an article (as well as tracking down photos for usage, full credit given) of the three operations at Magic Mountain/Heritage Square for the next ON TRACK Webzine. I had heard there was a vertical-boilered "Tom Thumb"/Grasshopper-type locomotive that was used on Ed Gerlits' 2' "High Country Railroad" and was curious as to if anyone had any details on what it was, who built it, and what use it saw. I haven't heard much else about it.
I was also curious if perhaps anyone here was involved either of the three operations (Magic Mountain, High Country RR, or the Rio Golden) or has a stockpile if information on either operation that might be interested in reviewing the rough draft for the article so far. Anyone who can help, please contact me via ontrack @ bjwrr.com
In addition, I'm also scouring out details and information on Hal Wilmunder and his "Camino, Cable & Northern" operation along the I believe Diamond & Caldor line up in El Dorado County, and the Antelope & Western in Antelope, CA. Any info greatly appreciated, and photos too.
Thanks for your help
Ed Kelley