I seen your post dated a couple years ago. I, too, had a grandfather who fought in the French Indian War. He was a Captain and a DAR Patriot (I dont know what that means).
His name is WILLIAM DOUGLASS b-c.1720, Chrles Co., MD. d-1786, Franklin Co., PA. Married a "Rachael" in 1746.
The reason I'm asking is because I hit a brick wall at WILLIAM DOUGLASS and Im hopeing that searching a different avenue may bring a result.
If you can help share info you may have aquired, I would be so greatful,