"He was on his own in South Africa when he died, Why?"
Not wholly clear, but when his relationship with the Company came to a bitter end he was ailing. He was also being pursued for a considerable sum of money by the new Board. So he set off for South Africa, presumably in search of warmth for his health and perhaps also for some peace and quiet, away from his troubles and disappointment. It is of course possible that his marriage was not all that satisfactory either. (I once heard, many years ago, comment that he had always been “a bit of a lad” as far as the fairer sex was concerned - but that could have just been a scurrilous rumour). Nothing appears to be documented about his domestic situation and something like that probably would never be anyway. It might well be that he undertook the journey with every hope, on his part and that of his wife, that he would return home as and when his health recovered.
What does seem certain is that he went alone, having abandoned his Aston constituents, and never returned. He was dead within 14 months. I’m not sure if you have seen “Under Five Flags” but the comment there is that he died in self-imposed exile and comparative poverty in Johannesburg and that “he never achieved the long-promised reunion with his family, even to attend the marriage of his only child Gertrude”. It was a sad end to a remarkable man.
If there any other snippets of information about him at that time, they are as likely to appear in this forum as anywhere. Whether anything further is held in the Birmingham Reference Library, I'm unfortunately unsure.
Chris