I am getting data back from Easton now. Many thanks to their volunteers and their incredibly quick response. We will post some bits and pieces here.
William was involved in two properties. The first they can physically locate
This is the modern map that they emailed me.
I believe they said it surveys to about 180 some odd acres.
The second tract of land, though not exactly located, has quite a bit of history that can be attached to it.
As I would read this, he is buying land for the heirs of George Kohar, deceased. The land is adjacent to the land of Henry Kohar. I suspect the heirs are Magdalene Kocher and her two children.
Last but hardly least are actual photos of the original tax rolls, and they have those from 1775 to at least 1794. The 1794 one is interesting for the inscription “land only”. The researcher attached to my requests speculates that William has already moved to Greene Co TN by this time, and is paying tax just on the land.