Check out the old NZ newspapers at http://paperspast.natlib.govt.nz
"Henry James Miles" funeral notice, 1927, plus other mentions which are probably another chap.
Death records at https://www.bdmhistoricalrecords.dia.govt.nz
You can buy a printout for more info and less cost than certificates.
Coroners records for two different "Henry Mile's" are referenced in http://archway.archives.govt.nz
but these have restricted access.
NZ Electoral rolls have both Cyril William and Ian Norman, both living in Karori, Wellington - access these on ancestry.com