Well, the owner says the vines are thriving, and the pic from a couple years ago sure looks good, so I'm guessing that if I screw up the first batch of cuttings, I can probably get more.
I can't imagine this is the ONLY VINE LEFT EVER, particularly if Bob's friend has 800 acres in.

But they're sure not readily available.
Are there objective tests to determine what variety these actually are? Or is it a subjective "looks like, tastes similar, must be"?
My grandmother used to take them off the bunches and freeze them in ziplock bags. During the summer she'd give me a little dish of grapecicles.
Edit: Apparently there's one proper grape that thrives in South Louisiana:
http://www.wafb.com/Global/story.asp?S=14014518&clienttype=printable
I don't know if it matters that it's on the North side of Lake Pontchartrain and I'm on the South, but...
Would this be the rootstock I'd be looking for?