Fight and Be Right by EdT - After the Syndicalist revolution topples the British Empire in the late 1930s and replaces it with The Federation of Worker's Republics, South Africa becomes a refuge for the entirety of the British monarchy.
The Chaos TL by Max Sinister - Known as Australafrica, Australia for shot.
Protect and Survive by Macragge1 - South Africa is heavily affected by The Exchange, and outside of a few refugees aboard a rag-tag evacuation fleet that reaches Britain, essencially seizes to exist as a nation.