Olson Imbs Family, Ims Farm, Hole nr Stavanger

I am interested in finding relatives of my great-grandfather, Mathias Tanke Olson Imbs b. 1842 who settled in New Zealand in the early 1870's. He was a farmer and bridge contractor. It is known that at least 3 of his siblings emigrated to USA or Canada. Family was: Soren Olson b 1833, Helberg Lene Oson b. 1835, Bore Reinhert Olson b. 1837, Kirsten Marie Olson b. 1838, Olaus and Johanna Olson (twins) b. 1840, Mathias, Ole Andreas oslon b. 1844, Lauritz Berhardt Olson b. 1848. I do not know when he came to NZ but he married my great-grandmother in 1871. Any information would be great.