Brian...
Sorry about my carelessness in posting that Grove Farm was on Maui. Give me a little slack, I haven't been there in thirty years.
In Fred Westing's book, "The LOCOMOTIVES that BALDWIN built", there's a nice photo of locomotive #1, an 0-6-0. (The caption that author Westing has written is really stupid.) If I'm not mistaken, the railroad was 30" gauge.
For good information about the railroads in Hawaii, go to either one of the books by Jay Conde. He was a Pan American flight engineeer, with enough senority to own the San Francsisco-Honolulu run. He spent his time there researching the railroads, and wrote two fine books. He was a good friend.
Bob Keller