His page on FindaGrave says his parents were Roy Shook and Pearl Miller.
I'll keep looking for records......
Does this help?
His obituary at Pulliam Funeral Home says the same thing.
I believe this to be Roy's Death Index,
and his Draft Registration Card.... here is the original image
This 1930 Census shows Roy Shook and Pearl living in Robinson, Crawford, Illinois just 3 years before Argo's birth in the same place.
Here is the 1930 Census Record.
Here is a 1900 Census for Granville, Jasper, Ill that needs further investigation. It shows possible parents of Roy to Francis F. Shook and Emma J.