Since the Masterpiece toys are pretty popular here, here's a add on for the Optimus Prime one that came out in 2004. It's a hand that can fit onto OP's arm over where his hand is (duh) and holding a little Spike pvc. This is actually an official ad on, like the trailer originally was. Most MP add on kits are 3rd party.
Speaking of MP, those rat bastards just had to do Rodimus Prime when I'm broker than shit...