Surname from death record of wife on New Zealand BDM website in June 2020:
1994/43389. Campbell, Winifred Joyce. Date of birth: 8 May 1921.

First two given names from New Zealand Electoral Roll - Waitomo Supplementary Roll No. 1, 1949, found in June 2020:
Campbell, William Donald, Te Kanawa Street, Otorohanga, caterer
Campbell, Winifred Joyce, Te Kanawa Street, Otorohanga, married

First two given names from New Zealand Electoral Roll - Taranaki Main Roll 1978, found in June 2020:
Campbell, William Donald, 2 Seaton Street, New Plymouth, Retired
Campbell, Winifred Joyce, 2 Seaton Street, New Plymouth, Married

Year and country of death, date of birth, from death search on New Zealand BDM website in June 2020:
1979/29416. Campbell, William Donald. Date of birth: 18 October 1900

Full date of death of 3 March 1979 from further searching in June 2020 on BDM Search by incrementally changing the date range for the death.

Place of burial, confirmation of date of death, from Taranaki Cemetery records found in June 2020:
CAMPBELL, William Donald, 3 Mar. 1979, 78 yrs., N.P. 4920

Confirmation of address with 1978 NZ Electoral Roll further above, from cremation information from New Plymouth District Council search in May 2020:
Last Address: 2 Seaton Street, New Plymouth
Age at Death: 78 Years
Date of Death: 3 Mar 1979
Category: Ashes Burial
Funeral Director: W Abraham Funeral Home, PO Box 4016, NEW PLYMOUTH 4340
Date of Burial: Not recorded
Cemetery: TE HENUI
Location in Cemetery: Services Cremation Block B Plot 73

Country of birth, name of parents, from search on New Zealand BDM website in June 2022:
1901/12325. Campbell, William Donald. Mother: Jane Sophia. Father: John Henry Allan

Date of birth of 18/10/1901 confirmed from further searching in June 2022 on BDM Search by incrementally changing the date range for the birth.

Year and country of marriage from search on New Zealand BDM website in June 2022:
1942/10087. Bride: Winifred Joyce Gray Groom: William Donald Campbell
Full date of marriage of 22 June 1942 from further searching in June 2022 on BDM Search by incrementally changing the date range for the marriage.