I would suggest you post in Georgia if you have not.
Just last summer, I found a long lost ancestor that was buried under his own name,
surname misspelled, in Savannah, Georgia. I could not believe I had actually found
that as finding a CSA soldier in a marked grave is not the most common thing to do,
but it has been done.
So my best advice is just continue to search, and in time, you may learn his final
resting place. Good luck.