Thank you Jorose. Yes, that is him. The problem is in knowing exactly when he arrived in the USA, though the consensus of opinion is that it was in, or before 1878.
And, how he arrived (it would have had to be by ship, of course) and where he made landfall.
As he went to the goldfields in New Zealand in 1867-ish it seemed to me that he might have moved on to the goldfields in America, or Canada.
The tale he told to the Floridians at the time was that he'd arrived in search of his stepfather, a Dr. Isles, but he was so creative with the truth in the stories he told people, that this is hard to establish.
Again, thank you,
Jamie