Ron,
I don't think there has been "probably absolutely" a mix up between 1896 and 1899. Although the Dutch N. H. began in 1899 with their import of 12 brood fish, their first fingerlings from these were not available until 1900. I think most of these, just over 4,000, stayed in Holland in any event.
In the book 'A Complete Guide to Freshwater Fishes of South Africa' by Paul Skelton it states that "Early writings indicate that carp were introduced to South Africa in the 1700s, and several importations are reported from the 1800s". Paul Skelton unfortunately doesn't quote references for his statements.
A scientific paper 'Introduction and present status of exotic carp in Africa' by J. Moreau and B. Costa-Pierce states, in the section on South Africa, that "In September 1859, Mr C.A. Fairbridge of Cape Town introduced six Cyprinus carpio from England as ornamental fish for angling. A further consignement was imported by The Cape Agricultural Department in 1896." These fish came from Bavaria, in the Federal Republic of Germany - not Holland. References, as would be expected in a scientific paper, are quoted.
Is this is where your 1896 comes from Ron?
The Food & Agriculture Organisation of the United Nations has the first introduction of carp into South Africa as 1859 (presumably the six fish from the UK).
Hopes this helps refresh your memory, Ron (which is a poor tool for retaining facts in my opinion!).
Kevin