I've been making replicas in silver of historically significant Nara, Heian, Momoyama and Edo coins as a hobby and selling them to collectors in Japan via Yahoo auctions .jp . When I stumbled into this forum I was pleasantly surprised to see the classified ad section.
The best seller is the Eiraku Tsuhou and I'm sure you're aware of its significance. Might make a nice award to the victors, just as Hideyoshi gave them out after battles. Please take a look. The inventory changes as coins are sold. Each coin is handmade and unique.