Nice, a few months back I saw a couple for sale on the bay, best of luck in your search. Im my case it's a 1732-1772 8 Reales coin, also known as a "Pillar dollar", "Piece of eight" or "Dos mundos"... Someday.
Wow those are certainly neat. My main goal is trying to get one of each pre 33 gold coin. Golds not cheap so thats quite an endeavor right now! Best of luck getting those coins!