Looking for a search angel that can perform a miracle...

Here is the very abbreviated version of my story. I was born on 9/24/70 from birth parents who were from "a suburb of Chicago". My birth parents ran away to CA when they found out they were pregnant with me, had me and then presumably moved back. When in CA they used false names (she used the last name Carter and he used the last name Johnson). So - what I have to go on is my birth families non-identifying info. Here is what I know: Birth mother's mother was an art teacher (in this suburb of Chicago). Birth Mother had 4 sisters and one brother. Birth father's father was a corporate attorney in IL. Birth mother's family moved to a small town in WI sometime in late 1969 or 1970. There is the smallest possibility that my birth father didn't use a false last name and that his last name was indeed Johnson. Some thoughts I have on searching; looking for art teachers that left a school in 1969 / 1970 (because of the move), looking up corporate attorneys during that time frame with the last name Johnson and checking to see if his personal information matches the non-identifying information that I have, possible real estate transactions in 1969 / 1970 in IL and WI with matching names... Oh - birth mother was 16 and birth father was 18. I have the ages and information on their siblings if it's helpful. Any thoughts or ideas on how I might accomplish any of this? Like I said, I'm looking for a miracle worker. Thanks in advance.