Year and country of birth from search on New Zealand BDM website in February 2021:
1912/11899. Oliver, Brian Elliot. Mother: Violet Constance. Father: Alfred William

Full date of birth of 8 February 1912 from further searching in February 2021 on BDM Search by incrementally changing the date range for the birth.

Occupation, year of marriage, from an online family history written by daughter Helen Oliver found in February 2021 from:
https://wordpress70995.wordpress.com

Year and country of death, date of birth confirmed, from death search on New Zealand BDM website in February 2021:
2004/17567. Oliver, Brian Elliot. Date of birth: 8 February 1912

Full date of death of 30 July 2004 from further searching in February 2021 on BDM Search by incrementally changing the date range for the death.

Country of marriage from search on New Zealand BDM website in July 2021:
1941/7223. Bride: Gladys Eleanor Acton-Adams. Groom: Brian Elliot Oliver

Full date of marriage of 5 July 1941 from further searching in July 2021 on BDM Search by incrementally changing the date range for the marriage.