RE: Cull buck?
I don't know dude if he's only 2.5 this fall, which I agree that is what he looks to be, he's got some really good beam length and awesome G2s for a 2.5. I'd let him walk if I were in your shoes to see what he turns out as a 3.5. If he gets another G3 you get all of your H scores and he'll have towering G2s and great brows. He'd probably gross close to 140".
FWIW, I'd have a hard time letting him walk in PA.