I have gone to the Watts-Hays Letters site... OK It would seem that John Watts (1786-?) and John S. Watts (1787-1860) are two different people, but... John Watts "The Indian Trader" from North Carolina and John Watts of New York (bef.1705-1775) are about the same age and were in The New York area at a time?
With what I have briefly read at the Watts-Hays Letters site, and what I read at "The Will Emory Site" I would assume that John "The Indian Trader" Watts might be correct, for both sites discuss similar directions. For me it razes the question if John "The Indian Trader" Watts and John Watts (bef.1705-1775) are one of the same or possible cousins?
P.S.: I found "The Will Emory Site" in my researching Maj. Emory of Mexican-American War Fame.