Since you are in Capetown SA there is a moderator to the MBWorld.org forum who lives near Haut Bay. He might be able to help you find a Boxster engine in SA. His name is Glyn M Ruck and he's a wealth of information on MB.
Here's a link to one of his posts.
https://mbworld.org/forums/members/86796-glyn-m-ruck.html
I had the good fortune to be in Capetown during world cup in 2010. It's one of the most beautiful places I've seen in the world and the people are very special. I hope it doesn't change!
Best of luck.