If my assumption regarding the copper is true, is there any ground
chemistry changes produced by the vines themselves?

Probably, but not anything I, personally, would give any concern about
whatsoever.

Ooops, I think you misunderstood me. I'm not concerned about ground
quality changes or anything like that, I'm looking for a method to
detect old (several centuries) locations of vineyards. If copper was
used as a fungicide before 1800, then copper concentration
measurements might be worth a try.

Does anyone know if copper-lime fungicides are used for other crops
than for wine? Anything I might have to consider mistaking for old
vineyards (planted on south facing hillsides, treated with copper)?