There is one other possibility. Every veteran got a document called a "DD 214" when he was separated. It states in concise form a lot about a service man's term in the military. Many vets were advised to have a copy of their 214 filed with the Recorder of Public Documents (it may have a slightly different name where you are) in the county in which they lived. Unfortunately, the 214 doesn't have precise details like unit designations and battles fought.