Hello Ann
To answer your original question - it appears 53 Khyber Pass Rd was apartments, most likely bed-sitters (see the Wises Directory extract below). This area is now either commercial/light industrial businesses OR taken for roading purposes.
As for his 'soldiers grave' - in NZ we honour returned service personnel by allowing them to be buried in specific 'services' areas located in most public cemeteries. The care of these areas is undertaken by the NZ section of the Commonwealth War Graves Commission and the Veterans Affairs Department. So it's unlikely he was a 'career soldier' - a check in the relevant electoral rolls would show his occupation through the years.
Best wishes
Elli
1938 WISES POST OFFICE DIRECTORY
Khyber Pass Road, Auckland
on the right from Symonds Street
... Auburn Street
49 HUTCHINSON Bros Ltd, grocers
51 MILLER Mrs J
53 WIGG Mrs RE, apartments
55 PATTENDEN George F
57 CORBRIDGE Frederick
57 ADAMS Mrs Florence
Severn Street ....