Searching for birth family of David Mobley- DOB July 20th, 1954 in Little Rock

My name is Lisa (full name Alisha Mobley McGuire) and I am looking for my biological family on behalf of my late father, David Mobley. David (Dad) was born in Little Rock, AR on July 20th, 1954. He was apparently adopted at the age of 6 months, and he was taken to be raised in Fort Smith. His home life was not a happy one and he spent most of his adult life estranged from his adoptive family. He joined the USCG at 17 and married my mother in Oregon in 1976. I was born in '80. David passed away on the 4th of July, 2014, just a few weeks short of his 60th birthday.David knew next to nothing about his biological mother and father. All he was told is that his mother was possibly a hair dresser in Little Rock and that's it. A second birth certificate was issued with the adoptive parents listed, but we are not sure we can even trust the information it lists. My mother is planning to request his adoption records from the AR Dept. of Health but I'd still like to reach out in the hope that I will find one of Dad's close biological relatives here. Please contact me if any of this sounds familiar. Thank you!