Contact, Cosworth, Ilmor, Judd etc, for a start. It can't hurt.
Failing that, Ebay, or motorsport auctions or classifieds, like at the back of Autosport magazine. My friend actually has a piston from a Cosworth V10 (Jaguar era). It is a beautiful piece of engineering, I must say.....
The "Ferrari Store" in Maranello. It's directly across the street from the entrance to the Ferrari factory and next door to Il Cavallino Ristorante. When one of the factory drivers bends one of their racing cars or lunches the engine, they sell off the bent bits there. They come with a testament of provenance.
The journal arrangement of a 10-cylinder engine's crank was a mystery to me until I saw one on offer there. It's still a mystery.
i want to make my head turner bnw Punto even better, yes wishing to do chrome on window edges and rear/front bumpers. please suggest, if somebody is offering such services .