I bought this single stamp from a seller in Canada.
It’s the highest value stamp (10 shillings) in the series known as the 1927-1930 London Pictorials; the last South African stamps printed in London.
(After that stamps were printed in South Africa).
The Afrikaans-English se-tenant (joined) stamp pairs are very expensive (up to $200), but the single ones are $10 or so.
I’m still looking for an English one with ‘SOUTH AFRICA’ inscribed at the top.
Issued 1927, Mar. 1
Perf. 14 | Engraved printing | Wmk. Multiple springbok’s heads
29 16 | 10sh | Bright blue and brown | Cape Town, Table Mountain and Table Bay
[Source: 2016 Stanley Gibbons Stamp Catalogue for Commonwealth & British Empire Stamps 1840-1970)
My notes: The prominent white tower might be Mouille Point Lighthouse— built in 1842 but demolished in 1908. To its right and further back would be Cape Town City Hall, a large Edwardian building built from honey-colored oolitic limestone imported from Bath in England, and located on the Grand Parade.
It was completed in 1905 and is still there today.