Has someone checked the persons name and date of death ( Do you have them? I can't remember.) with all the Cemetery Offices in the area. I have to ring my local office on occassion as I do War Graves and that shows the amount of names sometimes that you find in one grave. You may be looking at Smith and then also on the headstone there could be up to any amount of names. I have found my local office extremely helpful. Plus I took some American Friends to the Grandparents graves in Newcastle. I actually via mobile phone was guided to the unnumbered grave it didn't have a headstone either. People are fantastically helpful at times. Regardless whose grave he is in if the dates are there they can look it up for you and ring you back. They may even suggest if you have the info someone may go in and look through the books they have for each Cemetery,
Its just a thought,
tisgrannie