William Kerr from Dalry IN Ayreshire

My grandfather William Kerr arrived in NZ around 1901 and married Clara Tompkins. His parents were William Kerr (a vet) b1836c and Agnes nee Allan (my gt grandparents). They had three children that I know of. William's parents (my gt gt grandfather) were William (a blacksmith) and Elizabeth. Thats about as far as I have got. I am stuck. I am curious as to which Kerr side from the Marches on the border I belong to. If any of this is familiar to anyone out there I would be interested in hearing from you. I understand that my grandfather and gt grandfather came from Dalry in Ayreshire.