Help finding James Thompson, Cape Town

[annie10]

I have had a look at the sites suggested for researching in South Africa and i am still confused about how to find information on the person we want to find.  James William Thompson b 25 August 1919 at St Peters Pass, Oatlands, Tasmania, Australia and d 5 August 1972 Cape Town, South Africa. He was in WW2 and we think served in Egypt and came to South Africa sometime after the war  married Monica, surname unknown. That is all the family know about his later life.  His brother and sister are now in their middle 80's and not in the best of health and would like to know more about him and Monica and any family they had. James did have 1 child, a girl b 1941  to a lady in London and that is about it. Thank you.