I am looking for any information of the Koerner family in Namibia, Afrika.

I do not know the name of my great grandfather, but he had children with a namibian woman(my great grandmother)don't know her name either.He must have arrived in Namibia in the early 1900. I found a record of an August Koerner , a farmer who married a namibian woman , but I cannot be sure it is him. All his children have passed away already. Some of the names of the sons are; Ernst Heinrich Koerner,Max Koerner, August Koerner.

Thank you.