Hi there.
My name is Catherine Slade. i am also living in cape town and have recently been doing some research into my family history. i found some notes that my great granny's sister made. i came across the surname "Loock". It says Johann Christiau Loock a prussian officer left Germany and fled to south africa, having fought a duel which was a punishable crime, he assumes the name Loock, saying his real name will be revealed in his papers after death. these were unfortunately destroyed by step relatives, so his real name was never disclosed. Loock continued.
Johann Christiau married 15th sept 1782 to christi (rest of the name is cut off) Wilhelmina Hellen, daughter of capt. Hellen who arrives at the cape with his family on his way home from the dutch east indies- they have one daughter; Anne Catherine. so it seems the Loock name doesnt continue this line. then i have some facts on her marriage and lineage.
This may have nothing to do with your family and make no sense but i thought it could be interesting because i have found hardly anything on the name loock in south africa and would love to know Johann's original surname.
Best of luck,
catherine