[Sassy]

If its attacking you now it will only get worse as its hormones get going. There's only one thing to do ................... . 
The silkie at 10 weeks was at a critical age when they can just pop off, however, it is wise not to be complacent which I'm sure you won't be.

[evie2]

If you really want to keep the Orpington, ask the previous owner what they did to get the upper hand or could this be the reason they got rid of him?

[joyfull]

the two guinea fowl I got given a while back were very aggressive - however the previous owners said they just gave a little peck to the back of the leg. Within a few weeks of them finding their feet I realised why they had been passed on (and been passed on by several other owners it seems) they were very aggressive drawing blood on us and anybody else who visited our house. The deed had to be done as I couldn't take the risk of rehoming such aggressive birds. People will tell all sorts of fibs to pass on bad birds rather than doing what they should and that is culling them.
There is no need to have aggressive cockerels - I have had loads of good tame boys and only the odd bad one (which I never raised myself). Get rid of him and look around for a new boy - cockerels are easy to find and usually are free