Neil, Your post was quite some time ago, but maybe someone will notice this who can add to my knowledge.
I'm trying to figure out how come one William DINGLE is the grand nephew of the Richard ROWE who died in New Plymouth, Taranaki, New Zealand in 1875.
Richard arrived in New Plymouth on the William Bryan(t) in 1841, alone.His obit says he came from Marhamchurch in Cornwall, and his will left money to his sister Betsy CODDEL of Marhamchurch and her 2 eldest dtrs (and to his wife Mary, and an Elizabeth Caddy DAVIES, relationship unspecified).
I was very interested in your post which had a DINGLE and ROWE link, until I saw that you thought your William DINGLE had arrived in 1897.Although, thinking about it, it doesn't disqualify him from the connection as nothing actually states that William DINGLE is in New Plymouth, it just implies he was a minor at the time the will was written (the day Richard ROWE died).
My investigations to date had assumed that the William DINGLE benefiting from the will of his great uncle Richard might be the W Rowe DINGLE who is buried in Te Henui Cem. in New Plymouth, died Dec 1904 aged 46, married to a Harriet who died Jul 1929 aged 65.
My interest is actually the ROWE connection, as a family of Marhamchurch ROWEs married into my own Devonshire ROWEs.