An appellate court ruling has revived a man’s efforts to release a North Shore suburb’s police files in a 53-year-old murder case.A 1st District Appellate Court found that public bodies, including the village of Kenilworth, could not assert a blanket exemption over John Q. Kelly’s requests for the investigative files into the 1966 murder of Valerie Percy.Percy was the daughter of prominent businessman Charles H. Percy, who was running for the U.S. Senate at the time. Her murder remains unsolved.“[D …