He was 67 years old at the time of his death.
Profile dates (William was born in 1892. He passed away in 1956) make him 64, so one of them must be incorrect.
Agree with Deb
. U.S., Social Security Applications and Claims Index, 1936-2007 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2015.