Searching for Maj Rory Hassall and family

I'm trying to find relatives of my uncle Maj Rory Hassall who died in Durban South Africa abt 1994.
Married to Edna Nina Hood (known as Cherry) also died in Durban.
They had two sons Christopher and David - schooling at St Andrews College Grahamstown South Africa
Rory was in the police force in Swaziland, Botswana then Bechuanaland Protectorate) and Act Commissioner of Police in Fiji until the riots of 1959
It's amazing how one looses touch with family and even with the internet today can't find a trace of them
Hope someone can help
Garth