José's in South Africa

I have read with interest the stories of the origin of the surname José and I too was told the Armada story.From what I understand, the José's that I am related to came from Redruth in Cornwall to South Africa and my grandfather Reginald was born in what is now known as Johannesburg but was then Ferreira's Camp.I am trying to trace this section of the family back to Cornwall.My father Roy Calvert José mentioned that he thought the family name in Cornwall was George Miller José.

I would appreciate any info reagrding the above.
Thanks
Barbara