I suggest getting George's death certificate and obituary. Check with the Delaware County Historical Society or the Philadelphia Free Library to see if they can help you find the obit. The PA Div. of Vital Records would have the death certificate.
Since George and Josephine lived in Philadelphia for a long time it's possible the George Tipping listed in the 1850 census from Philadelphia at age 8 is the right one. He is listed with Mary Tipping age 53.