New York Central's 10th Ave Cowboys

I am doing research for two children’s books that I am writing, and I am trying to get information on the Tenth Avenue Cowboys of the old New York Central West Side Line. I was able to find some information on this site, in particular, about the Shays that were used on this line when the cowboys were in service. But I’m trying to get as much info as possible, and also trying to find out what was the last year that the cowboys were used before the High Line was completely in service. Any info is much appreciated.