You probably wont find exact proof but have to show how hospitals buried dead. And if you show he died in Okalona hospital then that gives you a connection. You just have to decide what cemetery you want to put the stone up in.. the Okalona Cemetery or one close to his home and family. I have done it both ways. We found 4 11th Arkansas boys that died at Silliman Hosp in Clinton, LA. The local cemetery has a large area where the Confederates were buried. We were able to get stones for them and we took them down there and put them up where they were buried rather than in our memorial section we have developed for our Saline County losses.
Every one of these stones represents a local soldier who was killed on battlefield, died in hospital etc who have no known burial location or it can't be identified. All of these say "In Memory" we have placed about 72 in our local memorial section of this cemetery. We have 265 soldiers who were killed or died but unforutunately, those whose names are on monuments at northern prisons, listed in a register with burial number etc, VA won't give a stone, says they are already considered marked. A few are marked where they died in other cemeteries across the South. It is definitely a labor of love for us here and our primary ongoing project. You have to find the info to proof death and burial and usually have to find a relative to request it. Sometimes you have to talk to the wall (VA reps) and try to explain, and lastly have to get in contact with Senators or Representatives to help push it through. Many of the folks there know me by name now as I call them personally. But eventually I can find the chink in their armor with research and details.