Looking for Mcdonald Mcmillan Agnew Families Scotland and New Zealand

hello Lesman,
The first Europeans known to have reached New Zealand were Dutch explorer Abel Tasman and his crew in 1642. In a hostile encounter, four crew members were killed & one body was eaten by Maori. At least one Maori was hit by canister shot. Abel Tasman sailed away to escape and Europeans did not revisit New Zealand until 1769 when British explorer James Cook, in the first of his 3 voyages, mapped almost the entire coastline. Then, from the late 18th century the country was regularly visited by explorers and other sailors, missionaries, traders and adventurers. They traded food, metal tools, weapons and other goods for timber, food, artifacts and water.

The first Christian missionary to NZ was Samuel Marsden in 1814. Marsden was a Yorkshire man who was both a Chaplin and a magistrate to the NSW penal settlement. He was known as the 'Flogging Parson' in his dealing with convicts. He arrived into the Bay of Islands with 3 families headed by Thomas Kendall, William Hall and John King who were all lay preachers.
By the early 1820s perhaps 100 sealers and deserters from ships were living semi-permanently in European–Maori communities on the coasts of southern New Zealand. Many were ex-convicts of English or Irish background, but there were also a few Americans (at least one of whom was black), and Indians (known as Lascars and Sepoys), who had arrived with the East India Company trading ships. The first women settlers, who landed in 1806, were the notorious mutineer and ex-convict Charlotte Badger and her fellow rebel Catherine Hagerty.

Captain James Cook was half Scottish and Scottish crew on board his ship Endeavour were the first from their country to visit New Zealand. Some of these early Scots stayed to live. John Nicol (‘Scotch Jock’, arrived in 1832) and Hector McDonald (born 1812) were both Kapiti Island whalers, and Alexander Robert Fyffe established a whaling station at Kaikoura. Nicol and McDonald were two of many early settlers who took Maori wives and fathered mixed race families. So was David MacNish (1807-1863), a Scot who settled at Raglan in the 1830s. The Love family of Picton and Wellington traces its ancestry back to the marriage of Mere Rere Te Hikanui to a Scottish whaler, John Agar Love. In the far south, George Newton’s marriage to Wharetutu (Anne) produced a very large family. In Moeraki, the daughter of a Scottish farmer and his Maori wife was Tini Pana (Jane Burns), who went on to marry H. K. Taiaroa, a Ngai Tahu leader.

One of the first ship load of assisted British immigrants was the 'Tory' into Port Nicholson (Wellington) 20 Sep 1839

perhaps you meant 1850s not 1650s and I believe they would have settled in Otago, Dunedin in particular?