Hi Monica, I decend from George Rex of Knysna too.My Grandmother is a Duthie. There is quite a bit of info, just not really online. Have a look at this site: http://www.aspeling.com/web/start/index3.htm#Ungererhttp://www.aspeling.com/web/start/index3.htm#Ungerer
Or try to get hold of the following books: "George Rex of Knysna" by Sanni Metelerkamp, date? "Timber & Tides" by Winifred Tapson, revised ed. 1963. "The Knysna Story" by Arthur Nimmo, 1976 (this book has a map inside the front and back covers of The Knysna in 1804 when Rex bought the area). "Genealogy of The Rex Family" by Arthur J. Rex Beddy, 1971. "George Rex: Death of a Legend" by Patricia Storrar, 1974. (this is the most factual book, as she proves that George Rex is NOT decendent of King George III and Hannah Lightfoot.It has a family tree chart inside the front cover.)
These books are mostly out of print but you can find 2nd hand coppies in SA.Just Google the name of the book.Abe Books is a great site for out of print books.
Good luck!If you have any success please let me know. If you have questions reply by this msg or contact me on my email address. Regards, Gabi