No problem at all.
The South African production line built those planes under licence, with the everything locally manufactured apart from the engine and instruments. I think around 160 of the 3 types were built.
The Westland Wapiti was the first one built, with construction of the first one on the production line starting in 1926. These were followed by manufacture of the Avro Tutor and Hawker Hartbees.
I have a very interesting book in front of me, that I'm reading again, called In Southern Skies by Jonathan William Illsley, that deals with aviation in Southern Africa between 1816 to 1940.
According to the book, and it seems supported by a brief perusal on the internet, the first powered plane designed, built, and flown in South Africa was in 1911, called the Raison Monoplane.
It was built by Alfred Raison, on the basis of an extremely general description sent in a letter of Bleriots monoplane.
Raison modified it by neccessity due to the sparse outline only given in the letter, giving it a tail skid and using conventional elevators instead of the moving tips of Bleriots plane.
Constructed of ash, with aluminium fittings, it took to the air at Rosebank, north of Johannesburg, on 30th April 1911.
There is a picture of it in the book, but as far as I can ascertain, there is no picture of it on the internet as of yet.
Another plane was also designed and flown in South Africa in the same year of 1911, by Adolph Brunett.
There are some other pioneers and their aircraft designs in the book, including 2 very probable glider pilots whos flights pre-empted the great Otto Lilienthal.