I would suspect the grave is no longer found if the burial is not listed in a cemetery book.

John F. McLeod was born March 1840 in Ga and was age 60 on the 1900 census for Middleton, Suwannee, Florida. with a daughter and 2 sons. What was the wife's name? Perhaps they are buried at the same place and she is listed.

By the way, is he a son of Finlay McLeod? There is a photo of him on Ancestry.com