One other thing, look at the smaller feathers that surround the base of the tail. See how closely set they are to the tail and how they are very rounded? In most cockerels that age these feathers are a little longer and starting to curve downward.
Given the information you've provided, I'm truly stumped on this bird. It looks like a black sexlink. Can you post pics of it when you bought/acquired/hatched it? I still think there is an age mixup.
Given the information you've provided, I'm truly stumped on this bird. It looks like a black sexlink. Can you post pics of it when you bought/acquired/hatched it? I still think there is an age mixup.