The date of death shown on the grave marker is actually the date of his interment.

N.H. Williams Passes Jan. 2

Neb . H. Williams, 56, a brother of the deceased Matt Williams, passed away in. a Rosemead area hospital on January 2nd.
Born February 2, 1913 in Missouri he was a disabled veteran of World War II. At one time he was a ranch foreman in Montana.
Survivors include four sisters: Mrs. Verba Clark of Bellflower; Della Bohannon of Idaho; Stella Longmar of Montana and Aslee Vestal of Missouri; also two brothers Chesa of Kansas and Dave of California.
Services were held Jan. 5th at 2:00 p.m with Rev..Bill Brewer officiating. Interment was in Mojave Cemetery.

Mojave Desert News January 1970

1930 United States Federal Census Record
about Neb Williams
Name: Neb Williams
Age: 18
Estimated birth year: abt 1912
Birthplace: Missouri
Relation to head-of-house: Brother-in-law
Race: White
Home in 1930: Willshaw, Toole, Montana

Father: Joseph Theodore Williams
Born: 5 Apr 1875
Hartville, Wright, MO, USA
Died: 3 Jan 1960
[city], Nevada, MO, USA
Mother: Olive Annabelle Wimberley
Born: 10 Apr 1880
[city], Wright, MO, USA
Died: 24 Jan 1961
[city], Wright, MO, USA
Marriage: 20 Aug 1896 in Hartville, Wright, MO, USA

Possibly Neb's first name was Nebuchadnezzar Williams.

Neb H Williams
in the California, Death Index, 1940-1997
Name: Neb H Williams
Gender: Male
Birth Date: 2 Feb 1913
Birth Place: Missouri
Death Date: 2 Jan 1970
Death Place: Los Angeles

Neb Haper Williams
in the U.S., Social Security Applications and Claims Index, 1936-2007
Name: Neb Haper Williams
[Neb H Williams]
Gender: Male
Race: White
Birth Date: 12 Feb 1913
Birth Place: Springfield, Missouri
Death Date: 2 Mar 1970
Father: Theodore J Williams
Mother: Anna Wimbley
Disability Status: Disability established - no record of type.
Type of Claim: Original SSN.
Notes: Mar 1937: Name listed as NEB HAPER WILLIAMS; 19 Sep 1996: Name listed as NEB H WILLIAMS

Neb Williams
in the U.S., Department of Veterans Affairs BIRLS Death File, 1850-2010
Name: Neb Williams
Birth Date: 2 Feb 1913
Death Date: 2 Mar 1970