Could he be a Black Copper Maran(s)? I have seen several pics and YouTube Video's and they have the spike right next to the comb but not behind the head. Could just be a variation in the breed... Perhaps you've already contemplated this breed. If not, hope this was helpful.
i'm thinking he might have 3 breeds in him...silcon buttercup with the comb type he has, he has our black copper marans coloration, and a polish crest...