I searched for his known “second” wife, and found a headstone that had a first name and last name on it that matched; although, her name was all that was known by family. This person shared a headstone with someone with a different first and middle name than that of my great grandfather, but had the same last name and approximate death year as my great grandfather, and shared the headstone with a women that had the same first name as his last known wife.
I then researched with that name, and found his death certificate. He had died in Missouri, not Oklahoma as thought; although, he was buried there. I knew I had the right record, due to the fact that his birth date and parents’ names matched. An unknown of daughter was the informant.
I ran a search for the daughter, and found a census with my great grandfather having yet another name.
I then ran a search for anyone with his last name (omitting a first name, as I do quite frequently), age and previous locations, and had then found that he had changed his first name and middle name multiple times throughout his life.
Not only did I find his death record as my father had wanted, but I was also able to find a second wife (the known "second" wife was actually a third wife) who was unknown of to the family, and a daughter he had with that second wife (a new aunt for my father, whom he never knew about), not to mention the fact that he went by several names throughout his life.
I’m still trying to solve the secret of why he kept changing his name. Was he hiding from something? I may never know. 😉