My aunt was the third wife of her fifth husband. In her Civil War pension application, she mentions having his family bible which included death dates of his wife and others.
I'm wondering what happened to the Bible upon her death. It's very possible it actually went to her family and left her husband's family altogether.
Could this have happened to one of your family items? It might be worth contacting descendants of an ancestor's step-child to see if they have any knowledge of materials of this type.