Turns out he has a lip tattoo, and given the numbers we can figure out (see So it turns out my new TB has a lip tattoo after all. #12 for some bad pictures of the tattoo), he may very well be Ezra, born in Ireland in 1997 (so 13 instead of 22 - he never struck me as an old horse, so I could believe 13 is right). His last races were run in Arizona, so him being retired here makes sense too.
So, he came to us with the name Gus (I didn't like the name too much, but I am terrible at thinking up names, so we went with it). Now I'm trying to go with Ezra (my 7 and 4 year olds like the name, but my 9 year old prefers Gus), but I keep slipping and calling him Gus.
I thought maybe a more Irish sounding name, something everyone in the family liked, would work better for him.