Surname from Muriel Leo’s (nee Oliver, 1917-1998) Family Tree.

Two given names, year and country of marriage from search on New Zealand BDM website in November 2018:
1922/6689. Bride: Emmeline May Victorine McKoy. Groom: James Forsyth Sinclair

Full date of marriage of 4 September 1922 from further searching in November 2018 on BDM Search by incrementally changing the date range for the marriage.

Year and country of death, estimated year of birth, from death search on New Zealand BDM website in November 2018:
1952/32005. Sinclair, James Forsyth, died age 64Y [Therefore born circa 1888]

Full date of death of 16 July 1952 from further searching in November 2018 on BDM Search by incrementally changing the date range for the death.

Year confirmed and country of birth from search on New Zealand BDM website in November 2018:
1888/10694. Sinclair, James Forsyth. Mother: Jane Ann. Father: Robert

Full date of birth of 8 October 1888 from further searching in November 2018 on BDM Search by incrementally changing the date range for the birth.