This 1914-15 star belonged to private James Veitch of the Otago Regiment. While his regiment saw action at Gallipoli, he did not. It was not until 1916 when he would first see service in France as a replacement for the Otago Regiment. Records vary but it is listed that he was wounded sometime in November of  1917 while serving in France. He was discharged shortly there after as being “no longer physically fit for war service on account of wounds received in action” 

Cool medal! I recommend some warm water, soap and an old toothbrush to remove that verdigris. Removing it will prevent it from further damaging the medal while leaving all of the patina.