John Siggins Death Certificate

Another Death Certificate that arrived from the LDS FHL yesterday is one for John Siggins, who died in 1931 at about 55 years old. I believe, but am not 100% sure, that John is the son of John C. Siggins and his first wife and is therefore my half-great-great-uncle (my paternal grandfather's uncle). I believe this is true primarily because I already knew he existed from census records, he is buried in the same cemetery as John C. Siggins and was buried by the same undertaker as John C. Siggins. If he is, in fact, the correct John Siggins, his mother, Mary Cavanagh, is John C. Siggins first wife, who's name I did not know.