I don't think it matters. It might matter for citizenship, if he was born outside the US. But for natural born citizenship, as long as his father acknowledged him, which he did in the divorce decree, then his father was not a US citizen, and thus he cannot be natural born.
Of course if he was born outside the US, and his parents were not married, then he would have been a statutory, citizen at birth, but still not natural born. If they were married, and he was not born in the US, not only is he not a natural born citizen, under the law at the time, he would not be a citizen at all. Unless later naturalized, but that's still a disqualifier.
I understand all that,have read 1000 threads on it. None of that is where the article goes.