That's not much of a wish considering the subject, but on the positive side, at least his can very easily become a reality.
I would make a 3-billion dollar bet with Carlos Slim, Bill Gates, and Warren Buffet that if they agree on a coin from any time in history (you did not specify the U.S. Mint...), I could magically disappear and reappear with that coin in front of their eyes.
I didn't say there is anything wrong with it, and in fact thought it a wise choice even if only because it's so easily obtainable. Even in a daydream thread, there's something good to be said for practicality.