You don't say what information you have for your father-in-law, and what exactly you are searching for. Are you looking for the names of his original parents? The name of his (possible) brother and contact with his descendants?
If so, what have you already done to receive a copy of his birth certificate?
The 1930 census for Kent, Edmunds County, SD lists Blaine as the son of John S. and Pearl R. JONES, with his parents' birth places given as the birth places of John and Pearl...