The informant was Wilson Bray's son Andrew Bray. It wasn't just Andrew who didn't know who his father's parents were. I haven't figured it out, either. However, there were several Wilson Brays in the family, so he is probably one of mine.
Also, even though the death certificate says that Wilson Bray was buried in Petros, there is a stone with his name at the Brayton Cemetery in Anderson County, and the Brayton community in Anderson County is very close to the Rosedale community in Anderson County where Wilson Bray lived. The stone says he was born 26 Jun 1879 and that he died 17 Aug 1922. The death certificate is probably correct that he died on the 16th and was buried on the 17th, and the stone is probably off by one day on his date of death.
Wilson's wife Susannah Phillips remarried prior to the 1930 census. Her second husband was Bud Goad. So her name was listed as Susannah Goad in 1930 rather than Susannah Bray.