John Wesley Hardin killed a man in Towash, Hill County, Texas. That is where I was born. I'm sure you are right about the burial place. However, many graves are marked with the name of outlaws of the old west where they are not actually buried. Example, Billy the Kid has two grave sites. Jesse James is said to be buried in Granbury, Texas and also in Missouri where he supposedly was shot. A friend of mine wrote a book about Jesse and claimed Granbury was the correct burial place. I've seen the grave site with tombstone in Granbury. Well, they dug it up finally, and it was a man with one leg, which evidently did not prove a thing, so the clutter about it died down.They dug up the one in Missouri also. Nothing proved. Even with DNA. It seems to be some sort of status symbol for a town to claim the burial spot for outlaws of the old west, gravestones and all. Nowadays, they practically 'throw them away'.
But, I've never heard another town who claimed John Wesley's grave so I feel sure you are okay on that point. Happy hunting!