I'm not related, just trying to help:

There's a death certificate for William Frank Key who died in January 1948 in Joplin, Jasper Co, MO. He was a widower at the time of his death. The informant on the death certificate was Mrs. Edna Claxton of Joplin. His place of residence is given as Seneca, Newton Co, MO. You can view the certificate at:

http://www.sos.mo.gov/archives/resources/deathcertificates/#...

1930 Newton Co, MO census, Seneca City, p. 5b
Frank Key head m w 65 wid MO MO MO carpenter
Francis E. Marley? grson m w 17 MO VA MO

1920 United States Federal Census
Seneca, Newton, Missouri
Frank W Key 53 head m w wid MO MO MO carpenter
Edna O Key 22 dau f w wid MO MO MO
Francis E Key 7 grson m w MO VA MO