West Side Lumber #4 is a Heisler. The 0-4-0T Porter named "Fido", which came 2nd hand from the American River Land & Lumber Co. has never been sighted to my knowledge. I have heard this rumor for years that it was in Texas, then in Oregon, and then in Nevada. There is an 0-4-0T that was located near a cement factory in San Antonio and is 36" gauge. Having seen the picture you posted on
Steam Locomotive Info, I would hazard a guess and say that one was built by Vulcan. Conrad's directory has no info on this loco either.
As for the diesel/hydraulic running there in S/A, I don't have much info on it. Does anyone have pics? I heard that the Red Train from Great America was sold awhile back and this may fit the description.