ISO Birth family 1953 Tulsa

My father, Michael Henry Murray, was born on June 6, 1953 at St. John's Hospital in Tulsa, OK. He was adopted thru a private adoption, at a lawyers office, at 6 months old. (Also, in Tulsa.) We believe his birthdate may be around 6 months off, as the photos taken on the day of his adoption look more like he was around a year old. However, the copy we have of his birth certificate states June 6. When he was adopted, he had polio and asthma. His adoptive parents were Jack and Imogene Murray. My father remembered a young girl (around 16) visiting him frequently and he believed she may have been his mother. Her family lived down the street with a last name similar to Adkins or Atkins. Around the time he started school, they relocated to San Antonio, TX and contact with the girl ended. My father died at 56 years old on August 12, 2009. He has 4 daughters, 2 grandsons and 2 more grandchildren on the way. We would like to find out about our biological grandparents, family history and medical history. His adoption records are sealed and every attempt we have made at having them opened has been useless. Thank you for any information you may have!