Bruce,
I have never seen a photo of the first locomotive that was found to not match the gage of the railroad, but from what I understand, it was an upright boiler locomotive named FLUKE. I wonder if that name was in reference to the gage mistake.
Oddly, another small railroad in the copper country called the Globe Tram Railway, was also built to 49-inch-gage. I could see the possibility of other railroads being built to that gage in order to use second hand equipment from the H&TL. However, the historical record I have indicates that the GTRY was built a few months before the completion of the H&TL.
There has always been speculation that the GTRY bought FLUKE from the H&TL, and that was the reason for GTRY adopting the same gage, but the dates don't support that theory.