Looking for siblings and information about my grandfather Giuseppe Nardi

Looking for siblings and information about my grandfather Giuseppe Nardi - Born in Palermo, July 21, 1886. He was adpoted OUT of the Nardi family by the Mirabella family but kept his name. I am trying to find his parents names and siblings. The church in the town burnt down and all records were lost. Any help would be appreciated. rpnardi@hotmail.com