Robert Hughes Mason (1830-1904) is a great-granduncle of my husband. His parents were Robert Mason (1800 -1870) and Elizabeth Hughes (1808 - ?). Robert Mason was born in Oxton, Nottingham and died in Pietermaritzburg, South Africa. Elizabeth Hughes was born in London. I don't know where she died, but it must have been in South Africa, as Robert left his farm (in Natal) to her in his will. They were married on 3 June 1828 in London.
Robert Hughes Mason is recorded on his death certificate as being born in London. He is recorded as living in central London (St Margaret Lothbury) with his parents and siblings in the 1841 census. He married Emma Bird in 1866 in Pietermaritzburg, Natal, South Africa, which is where he died in 1904. His death certificate states he had no children. This is where we still live. I hope this is helpful in sifting out which Robert Masons are your family!