Looking for Robert Alexander Leathart Descendants of New Zealand

Hi I am looking for any information on the Leathart family from New Zealand, He was born in Kawhia, Otorohanga, New Zealand,in 1842 and died in Onehunga 25 Dec 1912. His first wife was Elizabeth Williamson died 1901 and his 2nd wife was Julia Addis. I believe his father to be Cuthert Leathart and his mother mary ann Stread. This is according to his death cert. Elizabeth and Robert had approx 9 children, my grandfather Henry Edmund Wival Leathart being one of them.
Any help would be greatly appreciated
Donna