Thats your timing cover, American Sport Bike, ebay or you can just powdercoat or paint that one. You could have pokejoe make you a custom one if he is still doing it. I have never seen a aftermarket one sold just plain black though.
all i did was drill the rivots out, tap the holes, rattle can the stock timing cover then used some nice hex bolts to put it back in place...looks store bought.