I would be very interested in any solid indication that sons / grandsons of George Rex of Knysna moved from South Africa to Australia.
There are a very large number of people in Australia, New Zealand and Niue who are descended from a George Rex who arrived in Tasmania in 1834. This George Rex was born in Ryton near Malton in Yorkshire in Sept 1790 and he married Jane Matson at Bridlington, East Yorkshire on 16 Nov 1813. Jane plus surviving daughters and a young son followed George to Hobart some months later in 1834 and then a month or two after Jane arrived, their eldest son William also moved from London to Hobart. Jane died in 1836 and in 1837 George married Sarah Jane Richmond in Hobart. So there are two lines of descent - the Matson Rex line and the Richmond Rex line.
Patricia Hayward has recently published a very comprehensive book titled 'The Ancestors and Descendants of George Rex ~ Born 1790 Ryton Yorkshire, Died 1858 Hobart, Tasmania'