He was apparently married in 1872 to Anne Watson Couper. Possibly in Christchurch, but I have also been told that he was married when he arrived in NZ (Although we can't find any record of a Thomas Marson of the right age arriving in NZ either, so we're unable to authenticate either claim).
He was a farm labourer in NZ. He died in 1909 at the age of 68 (Reported in CHC paper) after being struck in the head by a piece of farm machinery (A Hay Lift I believe).
He had at least 5 children. Emily Grace, Louisa, Thomas R G, William J, and Henry Francis Marson.