Looking for Cook S of Dunedin

I am struggling with the Cook side of my family tree and am hoping someone can help me out a bit.

I have Alexander Joseph Cook, born 1919, died 1988. He was married to Doris Kathleen Hodgins. Served in WWII.

His father was Alexander Cook, born 1889, died 1956. He was married to Elizabeth Renton Wedderspoon. Served in WWI.

His father was Joseph Cook, born about 1869, died 1943. He was married to Esther Magee.

The problem i'm having is getting any further than that. They are all Alexander's and Joseph's in this line it seems, so it is hard trying to work out who is who and who comes next.
Any information anyone might have would be extremely helpful!
Thanks.