Many thanks, Jay. I'm going to have to write this out in a chart to get the full picture, I think.
The reason I was asking is that my husband has a cousin who insists that the family lived in Grant's Corners even after I sent her the exact lot number and succession of generations at 2nd SSRR. So I was wondering whether there might be some basis for her belief.
Now I am wondering if it's possible that [Donald] Alexander Grant (patentee of lot 15 above)'s father, Alexander Grant (1733- 1791) might have lived there, perhaps as a tenant, since Anne has pointed out that his wife, Marjory Grant, was the sister of John Duldreggen's mother. And because I don't know where this Alex lived (though my best guess is Cornwall).
I suspect, though, that the cousin's family simply decided a couple of generations ago that their ancestors settled at Grant's Corners because of the Grant name and the proximity to both Williamstown and Cornwall where interim generations lived.