As thin as he is on mass, I'd 100% agree with Kelly on getting him early. A spike buck could break him off in many places. And you are correct in your re-assessment of age. He is no more than 3.5. Shoulders are way to thin to be any older. IF you can hold off on him, and I know that is a mighty BIG IF, next spring try finding his habitat and start laying down some serious protein and phosphate blend supplements and see if you can get some more mass on that bugger. The way he is right now, a stiff wind could break him off.