Hi Rollo, thanks to your above info I can explain the question about the Natal Championships.
I have found this useful thread about Sugar Circuit:
and joining this source to your info we can write so:
Natal Sugar Championships
, Durban, South Africa (Hard)
It was an event of Sugar Circuit, sponsored by Hulett.
1962 Ann Haydon (GB) d. Annette Van Zyl 6-2 6-0
1963 Margaret Hunt d. Renee Schuurman 7-5 4-6 6-3
1964 Darlene Hard (US) d. Annette Van Zyl 6-1 6-2
1965 Ingrid Frohling d. Heather Nicholls Segal 1-6 6-0 6-4
1966 Annette Van Zyl d. Ann Haydon Jones (GB) 4-6 6-3 6-4
1967 Pat Walkden (Rho) d. Virginia Wade (GB) 6-2 9-7
1968 Annette Van Zyl d. Carole Caldwell Graebner (US) 6-1 6-1
1969 Billie Jean Moffitt King (US) d. Annette Van Zyl DuPlooy 6-4 6-1
1970 Billie Jean Moffitt King (US) d. Margaret Smith Court (Aus) 6-4 2-6 6-2
1971 Margaret Smith Court (Aus) d. Patti Hogan (US) 6-2 6-1
1972 Brenda Kirk d. Pat Walkden Pretorius (Rho)
1973 Sharon Walsh (US) d. Pat Walkden Pretorius (Rho)
0-6 6-3 6-4
1974 Sharon Walsh (US) d. Brenda Kirk 6-2 6-1
1975 Linky Boshoff d. Greer Stevens 0-6 6-0 6-4
1976 Brenda Kirk Dimitriou d. Alison McMillan 6-1 6-2
1977 Elizabeth Truter Vlotman d. Alison McMillan McDade 6-3 6-2
1978 Alison McMillan McDade d. Elizabeth Truter Vlotman 7-5 6-2
1979 Elizabeth Truter Vlotman d. Alison McMillan McDade 7-5 6-2
1980 E. Barrable d. Ms Muller 3-6 6-4 6-4
1981 Rene Uys d. Beverly Mould 3-6 6-1 6-2
So it seems that this event put beside the traditional Natal Championships, whose full roll we have, that continued to be played in the same years.
But it oddly seems that the other South Africans events (Orange Free State Champs. in Bloemfontein, Western Province Champs. in Cape Town, Border State Champs. in East London, Eastern Province Champs. in Port Elizabeth) were replaced by the events played for the Sugar Circuit. Or maybe we have incomplete info on these championships.
Rollo, your above roll seems wrong in 1976 and 1977, where I have found different results.