I think you need someone really experienced with hunting through the unindexed records of familysearch.org for a probate for Stephan Frank Barac, his probate would've been in 1959 in the Transvaal and it's ref is 1031/59.
Or his spouse Wynandina Barac (born van Achterbergh) who died on 7 May 1951, also Transvaal with ref 2614/51
The couple were married in Lydenburg, and Stephan was buried in Lydenburg as well. Stephen also married Hermina Catharina Vosloo (born Botha).
Good luck, and I hope this helps