Peter, I was able to find this link below that referred to a "James Sullivan, the well known horseman" and references another article with the date 1892 in it, so it might be the guy we're looking for, but since Google doesn't have the "cache" feature any more that highlighted search words and I don't have time to search the whole document (my lunch break is almost over), you are welcome to it.
In the article Vail posted, the man whose picture resembles Wyatt (at least to you and me) is identified as Joseph C. Sullivan. In other articles I've found and in DeArment's BAT MASTERSON, he is... more
Re: Thank you, Steve and Tom. Bob Cash,Thu Aug 2 09:54
Hi Bob Thanks for that. It seems to me the articles referring to Joseph Sullivan look more authoritative than the one - that I saw anyway - which refers to James C Sullivan and which says he was from ... more