Date of birth of 12 Aug 1800 given by David Lloyd in an email of 14 July 2007: “My mother's maiden name was Nola Orielle Bradley. Her mother's maiden name was Jessie Bertha Oliver b 31 Oct 1876 whose parents were Jessie Pollock (nee Higgie) b1847 and Samuel Oliver b 17 Oct 1833, whose parents were Ruth Grace (nee Batten) b12 Aug 1800 and James Oliver b 25 July 1805”.

Date of birth and death also confirmed by David’s son, Dax Eric Clayton Lloyd.

From Brian (of nzolivers.com) trip to New Plymouth February 2009, the Headstone at Te Henui Cemetery, New Plymouth, New Zealand:
Row14 Lot 3 Plot 01:
Sacred
To
The Memory of
James Oliver
Who Died April 1st 1886
Aged 80 years
Also in memory of
Ruth
His beloved wife
Who died Sep 4th 1868
Aged 68 Years

A date of baptism is given as 29 September 1799 by Peter (Pete) G M Dale of Toronto, Ontario, Canada. Added here in February 2014. Pete is related to the Olivers in Devon. Pete's great great great grandfather was John Batten (Battin) b. 1793, sister of Ruth Batten who married James Oliver b.1805. Ruth and James emigrated to New Zealand in 1841.

If Ruth did die aged 68, as per her headstone, she could of been born anytime between 5th September 1799 and 3rd September 1800. Therefore a date of 29 September 1799 would work. If so, Ruth must of been very close to her 69th birthday at the time of her death.

Place of birth and place of death, from Pete Dale’s updated family tree as at 2 March 2020.
Headstone inscription from Te Henui Cemetery, Block H Headstones, found in March 2022:
Row 1, Plot 1292
Sacred to the memory of JAMES OLIVER who died April 1st 1886 Aged 80 years. Also in memory of RUTH his beloved wife who died September 4th 1868 Aged 68 years.

Result from death search on New Zealand BDM website in March 2022:
1868/5585. Oliver, Ruth. Died age 68Y

Full date of death of 4 September 1868 confirmed from further searching in March 2022 on BDM Search by incrementally changing the date range for the death.