Taking the last first, I do know those vines. Must admit I’ve lost touch with current wines from that planting, but did write about them about 20 yrs ago when John Beuchsenstein was making the wine (he then went to Fife and now has Republic of Sauvignon) and the Keene family (do they still own it?) had Dr. Carole Meredith (UC Davis plant geneticist) authenticate the varieties in that planting. The vines are on their own roots, I believe. Now that you mention it, I’d better catch up. I wonder if they’ve been propagated, and where? As for markers of manipulation, that’s really frustrating. Obviously, the goal is for such techniques to be not apparent, or undetectable. That’s why I cultivate my own little KGB network of moles in various cellars, especially during crush. But generally, look for incongruities, like if it tastes like the grapes were falling-off-the-vine-ripe and yet there’s abundant acidity and moderate alcohol. If you just have a feeling that the wine was jacked around, it may well be the case.