Read all the posts and just wanted to suggest that you research his neighbors when checking on his land ownership. I could not exactly find a relative's ownership so I looked at deeds near his "property" and he was mentioned. " blank blank acres adjoining the property of..." Often deeds have mention of neighboring properties to define the sold or purchased property. Don't forget newspapers, especially in small towns. They told all the news and social info. of the area.
Don't give up!!