The CWGC site records that he was the youngest of the thirteen children of Charles Pluck and Caroline Mary Ann Pratt who emigrated to New Zealand in 1874. He was born in Rakaia, N.Z. on 1st December 1893.
He is PL711 in Tree 14.A copy of his military service record can be viewed. It is a 5.6 Mb PDF file but well worth reading. Click here to download it.
I am grateful to Neil Pluck for providing this document