I'm marking Paul Davidson as found on his Draft WW1 Registration card. I'd put the accuracy on this one closer to "more likely than not" than "for sure." But there's enough here to give me some level of confidence that it's the same guy.
Yes, I realize it says "Davison" without the "D" at the top; but it sure looks like Davidson, with the D in the signature. Anyway, if you've got a better lead let me know!