I have an digitized photo of this (the one from Henry County, TN)Matthew's grave stone, and I'll share with anyone requesting it. He--and wife Eleanor also reportedly--are buried in a field on the farm where they settled in the mid-1820s. The graves are just outside Paris, TN, less than a mile off Highway 54. Older local residents would probably identify the area as near the Camp Tyson gate from the Dresden highway.
Please note that this part of Henry County was never close to Benton County. Henry County contributed part of its southeastern area to the formation of Benton County, and I believe that a small area was in dispute for a short while.