WONFOR 1910

Good Morning all, 

Some advice/input needed please...

What documents would/should/could possibly be available pertaining to someone's youth. Born circa 1910, so I imagine he would have started going to school in Kimberley, South Africa in or around 1915 (His sister was born there in 196)...
Shortly thereafter the family moved to Cape Town. I have found records for 2 of his brothers, the older (born 1905) graduated from SACS in Cape Town, seems he only attended there from 1921 - 1922 when he completed matric (which also matches my records stating that the family moved to the Cape around 1921) and the younger, Norman, finished up his schooling at Wynberg boys High. 
I feel like I have contacted most schools and churches from that era but please flood me with ideas, I really need something from his youth.. 

Desmond John WONFOR, born in Ireland in 1910 but had no named listed on his Irish birth register. Have checked most SA records I can think of, wondering if he may have been baptised on the ship..Edinburgh Castle I have quite a few of the ship lists too, showing the family travelling regularly between the UK and SA.. but most only have initials and are not concrete evidence to link him to his parents: Joseph Edwin and Edith Maude..

Any advice would be appreciated. I have also tried to find evidence of the ship bell as I understand children baptised on board sometimes had their names carved into the bell but no luck there either, especially since the ship seems to have been sunk! 

Thanks in advance

Ps have not been able to find the family in the 1911 Irish census, which is also what leads me to believe they left for SA before it was conducted.