A Wisconsin store owner and a Nintendo collector have discovered a trove of 97 ultra-rare, uncirculated cartridges of Super Mario Bros./Duck Hunt, a game originally bundled and released in 1988. The cartridges, found in a storage unit, were manufactured in 1993, significantly after the game was discontinued.

Jason Ganos, a noted Nintendo collector and operator of the Nintendo Wire news service, was approached by Kevin Braun, owner of One Stop Wonders in Waukesha, Wisconsin. Braun had a box of Super Mario cartridges he had acquired years prior, with the previous owner intending to sell them for scrap metal. Ganos recognized their potential significance.

"It’s like pulling out like a Holy Grail," Ganos said of the discovery, noting the cartridges were "absolutely pristine."

Experts at Professional Sports Authenticator (PSA) graded the cartridges, with five receiving a perfect score of 10 on a .01 scaling basis. According to Ganos, no Nintendo Entertainment System (NES) cartridge had previously achieved a perfect 10 score. The exact reason for the 1993 production date remains unclear, though Ganos and Braun speculate they could be warranty replacements or part of an unfulfilled retail bundle.

Most of the 97 cartridges are slated for an online auction hosted by Golden Pop's Culture Auction, which began Friday and will run until September 9. Ganos and Braun will keep a few copies, including some rated in the high 9s, and one copy each with a perfect 10 score.

While the games are playable, Ganos expressed a desire to preserve their mint condition. "Finding uncirculated stuff for me is just like super exciting," he said. "This game was the first video game I’ve ever played. Mario Duck Hunt was just such a big part of my life growing up."

Ganos transported the cartridges to California in his carry-on luggage for verification and grading, a process he described as nerve-wracking. He noted that while ultra-rare video games can fetch six- to seven-figure prices, the unique production history and pristine condition of these particular cartridges make their value difficult to estimate.

Following the initial auction, Ganos and Braun plan to conduct a charity auction with some of the discovered games.