Google Earth Engage View/Historical Imagery and a slider appears at the top of the page that may show earlier photography. Sometimes earlier photography can be found to overlay on Google Earth by downloading .kml or .kmz files.
New Zealand Aerial Mapping - hold archival Lands and Survey photogrametry aerial photographs from the commencement of aerial photography onwards, obtainable as stereo pairs. An expensive commercial service. You cannot view before buying but they will respond with information on coverage. The contact is Chris Parkyn 0800 680690 Warren and Avenue Rd. Hastings 4122.
The Whites Aviation archive is held by the Alexander Turnbull Library but are currently being managed by the National Archives, 10 Mulgrave St Thorndon, Wellington. They appear not to be indexed in Archway.
National Archives - hold some obliques. Archway is their search site.
National Library Have aerial photographs amongst their holdings Matapihi is their search site.
DOC Projects Some can be seen at low resolution here. An index to the photographs is available here.
Kevin Jones also carries out flights specifically for archaeological site recording.
Many Councils have rectified photos, some on websites in mapping systems. If you are working for or with a Council it is worth asking and looking on their website. They may also have historic sets, possibly passed to their libraries.
Project Promoters may have obtained photographs for their purposes. Again ask.
Ruanga / Iwi have been enthusiastic adopters of GIS systems. As well as map information these may include relevant aerial photography.
Auckland Region ALGGI site gives an index to aerial photography but not the photographs themselves.
University of Auckland have NZAM stereo pairs for Auckland and a little wider. Map Room Auckland University Library. The contact is Brian Marshall 09 3737599 x 88452
Tonkin and Taylor Ltd hold NZAM stereo pairs and provide access as a commercial service through an annual subscription or an individual search fee. Contact is Paul Tudor 09 355 6000 105 Carlton Gore Rd, Auckland.
Department of Conservation Auckland hold an old photogrametry photo series.
Puke Ariki in New Plymouth holds local historic aerial photogrametry photographs.
Waikato University holds local historic aerial photogrametry photographs.
Koordinates has data sets including photography from many parts of the country. Some are free.