I am the grandchild of Riewert Buitenwerf and I that was a brother from uncle Job (your father Jacob). Is it right that your father had a fake eye? I can remember him from my grandfathers birthday or from story's that have been told.
Wel, if you want to know more than you can contact me.
My mother lives in Holwierde, Groningen NL and her name is Aafke Biemond-Buitenwerf. Her sister is also called Janneke.