Yeah, mine are just for fun right now, too! It's something I might get into later on down the road. But right now, I'm content with just breeding silkies. You said your Polish was 7 weeks, right? Well, they don't get in a crest until they are nearly mature. But I can already tell that the vault on the bird is a bit on the low side and the crest even at that age should be engulfing more of the head-- even with pin feathers. I'm guessing your bird might be a cross between a silver laced and a white crested... somehow you ended up with a mottled bird. Very interesting color, none the less! Actually, mottle is a color that is being worked on with Polish, but I don't know how far along in generation they are.
This is a Silver laced polish rooster: Silver laced Sebright
Anyway, the pattern for lacing is very distinct should look like this:
THIS is a mottled: (see the difference?) But this is a Houdan, not a Polish.
My opinion of your little Mohawk is that you have a very adorable little bird on your hands, but so far, looks to be a pet quality right now. But don't tell him that!!!