Tiko on Family Tree Circles

Been stuck on this one for 15 years and no one knows

Kenneth Matheson was in Metcalf Australia and his son John was in New Zealand . John went to the Boer War and returned to NZ He paid maintenance while away as he left a child by the name of John William Ferguson . He took his mothers name as she was Jessie Ferguson. We don't know but think that Dugald Matheson who looked after Sommes Island in Wellington had married a sister to Jessie a Alice Maria Ferguson . We would like to trace John William who was registered in the North Island