One obvious fault with him being a Old English, he has yellow legs. He would be an American game, and yes the cocks won't get along if they're true games even if raised together. Looks like a fine looking bird; but telling his individual line is difficult and not real important. I say he looks similar to a Kelso, but then some Clarets, Democrats, Radio, Yellow Legged Hatch, Butcher, etc. Look very similar as well.
God bless,
Daniel.