I thought I'd post this here, just for interest sake. I know nothing about this but apparently they are very rare and valuable? It's a Diskun Prize Disk. It was traded into the local game store by a collector who had some very special items like this. He also had a Mike Tyson signed "Punch Out" for the NES as well as a SMB3 signed by the Mario voice actor. Anyway the game store owner isn't selling the Diskun but will hold onto it for a while to see if the value increases. I took a picture because it seemed to warrant it as a very interesting piece of gaming history. I'm not really an NES collector beyond the few dozen games I enjoy but I thought some here might enjoy something like this.