Grandfather possibly sweeny

My grandfather was adopted in Louisiana by Travis' has searched for a long time to find his birth parents and found out thier lsat name was sweeny. He also had a adopted sister but the entire fmaily suggested they were birth ciblings b/c they looked so much alike. Unfortunetely his sister passed away some years ago and my Grandfahter had given up the search do to health problems. My father and I are desperitely looking for any information or way to find out birth parents real names. I have been told Louisiana is very strict about thier adoption records and we have a feeling that's the reason why my grandafhter had given up. He isn't doing very well with his health do to a heart valve replacment and being in his late 70's. My fahter and I would really like to find out this information for ym grandfather before he passes for him. Any info or advice would be great!