So the first pic is this iridescent, "leakage". And on a Sussex, if nothing else, this would tell us everything we need to know. Especially its location and how it is in a patch like this. They aren't always pointy initially, but they usually will be longer than a pullets.
Second are these few...
This is undeniably a cockerel. A very fast maturing one at that. Interesting to see his hackles and saddles coming in so quickly.
SS roosters are beautiful, you've got a real gem on your hands here.