Cornelius Jacobus Oosthuizen

Hi Guys,

I am looking for info on the Oosthuizens from especially the Brandfort region.

My Grandfather was Cornelius Jacobus Oosthuizen (1931-1991) Married to Johanna Isabella Odendaal. He had three siblings whom died at young ages.
My Great-Grandfather was Cornelius Jacobus Oosthuizen(1898-1964) who married Aletta Dorothea Griesel on 1924 in Brandfort, the Griesels are a huge family in the Brandfort region.
My Great-Great-Grandfather was Cornelius Jacobus Oosthuizen married to Cornelia Jacoba Matthysen, here is when the trail goes cold.

I think the reason why I cannot find anything further than my great-great-grandfather is because of surname variations of Oosthuizen as well as Matthysen.

Any help will be greatly received

Thanks!