Searching for my brother

I am searching for my older brother. His name is/was John, and I believe he was born in the the latter half of 1947 or early 1948. His birth mother's name was Ada May Smith, born on March 3, 1929. Her parents were Herman and Viola Smith, and the family lived on Baldwin Road in Grand Blanc. According to all the information I have, John was born in a home for unwed mothers somewhere near Pontiac. I may be a little off on the time frame of his birth, but our mother never finished high school, and she would have graduated in 1947. Instead, she received some sort of diploma or Certificate of completion (I guess it was like a GED back then) from a school based in Chicago in May of 1948. I first heard about my brother in 2001, and have been trying my best to find him since then. If you or anyone you know has any information at all that could help me find him, please contact me as soon as possible. I really want to find my brother. Thank You, Michael Shields