Hi Gay
I've used a slightly different approach to that of McKha

... and the info I've gathered comes from a variety of sources.
* Just remember though that the electoral rolls and directories do NOT always give an accurate view of where people were residing on a given date .... nor do they give details of every person residing at a particular address.
The
1928 Electoral roll for Napier shows (main roll) >
NORMAN - Stanley -
76 McDonald* Street - carpenter
[and as well - as per Mckha's earlier post - Jack Johnstone PATERSON, engineer - on Napier Supplementary roll - at 76 McDonald Street ]
[[Note : Stanley NORMAN's family were long-time residents of streets nearby to McDonald Street and it seems he was only at No. 76 for a short time before he moved to another street in same locality. Maybe the PATERSON chap was a lodger at the address ?? ]]In the
1930 NZPO Directory -
POWELL, Hnry* S. - storeman is at 76 McDonald Street[[ Note: Mr POWELL's forenames are actually Harry Sydney and he is at # 76 until the time of his death in 1940. ]]
1931 - Napier e/roll
POWELL - Harry S. - 76 McDonald Street - storeman
POWELL - Mary Ann - married[1931 - Jack Johnston PATERSON is still on roll at 76 McDonald Street

]
POWELL - Mary Ann at same address in
1943 (following Harry's death) ... also 1943 at # 76 are Harry's son and daughter-in-law (who later move to Kennedy Road.)
Now ... given all that guff

... the only reason I've mentioned these people is that in the
1933 NZPO Directory (Wise's), there is this listing (I think may be, of some interest ?)
POWELL - Hnry. S. - 76 McDonald Street - storeman
POWELL - Mrs. M.A. - 76 McDonald Street - Mtrnty home ... (Mtrnty I'm fairly sure is the abbreviation for "Maternity" ?? )SO, the question is, was Mrs M. A. POWELL (Harry's wife Mary Ann) offering "maternity / or nursing services" from # 76 McDonald Street, during 1929 ?? ~ Lu
Edits : to clarify information