A Hopi Grape Mystery

My brother-in-law is a traditional Hopi farmer in the village of Moencopi on the Hopi Reservation. He's also a conservationist interested in traditional crops and heritage plants of all kinds. There have always been old grape vines growing on the periphery of the terraced fields at Moencopi. In recent memory, nobody paid them much attention and they languished, but given the tenacity of grapes, especially old vines, they've stayed alive. My brother-in-law, curious about them, began to prune his and feed them a bit and they are responding to the attention by making fruit. He describes them as pretty thick skinned, not particularly sweet. Hmmm...sounds to me like they might be wine grapes. The skin to pulp ratio is much greater on wine grapes, table grapes having thinner skins, and more juicy pulp. I know, it's counterintuitive, but that's how it is. Wine is much more dependent upon a grape's skin that it's pulp.
I've found references to Hopis having grown grapes for generations. It's generally believed that the little stunted peach and apricot trees found all over Hopi are descended from cuttings brought by the Spanish and cultivated there ever since. The Spanish were expelled during the Pueblo Revolt of 1680, but their crop introductions had been found useful by the Hopi and remained. Anyone with even a whiff of Southwestern historical knowledge also knows that the Spanish carried grape cuttings with them pretty much wherever they went. There's no substitute for communion wine, and if you're going to establish a community and show the heathen savage the error of their spiritual ways and bring them into the Body of Christ, you gotta have vino.
There is every indication that these MAY be the descendants of Spanish grapes. If that's the case, they're no doubt related to the Mission Grapes of California, which are disappearing. The Mission Grapes made pretty low quality wines and today's modern wine industry in California isn't based on them. These grapes would be an historical footnote and a curiosity, not much more. There's also the possibility that they could be Mennonite grapes. Mennonite missionaries came to the Hopi villages in 1892 and there was a Mennonite mission in Moencopi until the mid 1980's. I'm thinking though, that it's unlikely that Mennonites would have planted wine grapes.
So in short, I'm going to endeavor to get these grapes identified. The first step will be to get some proper cuttings this winter when they're dormant. I've also been advised to get in touch with UC Davis' AG department, where they've done lots of grape research. I need to find out what kind of tissue samples they need and who to send them to. Details, details. It should be an interesting project. Stay tuned!