Richard, you may need to clear some space in your Inbox. Hopefully you will have received my answer to your PM, but when I tried to send a follow-up I was told you had exceeded your storage limit. The follow-up message was as follows:
When I clicked on the link I had given you to the Capetown baptisms to check that it worked it came up as unsafe, despite the fact that I had gone there via my safe bookmarks. Try your own search for University of the Witwatersrand, Johannesburg research archives. Of course these records may now be available on Family Search. If you have access to the family trees on Ancestry the children born at the Cape are listed there.