If you look on the find a grave site again, someone by the name of Alverne J. Hollingsworth has left a flower and a note. Her name is a live link so you can click on it and send her a message. She may have more information for you!
The note says: John was the son of William R Johnson & Julia Ann Flint; husband of Mary Elizabeth Dunn.
Scroll to the bottom, it is under the pictures on the right. Happy Hunting and Good Luck :) Kim