Sorry to hear your cockeral is misbehaving, James. I have to say though, we had to cull ours last year. He was vicious, and would fly up at you every day, with his feet turned so that he would get you with his spurs. Even if you were taking food in he would go for you. I drew the line when I bent over one day to put food into the bowl and he flew at my face- fortunately I was able to jerk my hand up and shove him away, but he managed to scratch my cheek and came so close to my eye. I blame myself for him being so aggressive, because we kept in shut in for a while after we got them, as we didn't have a run sorted, and I think it made him very territorial.
I know it might not be a good decision to make, but remember you might have to consider it. Good luck with him.
Beth