I refer you to puzzle SAC#537 in August 2013. It's a Cegga-Porsche, probably a rebodied Porsche 904, and I'm guessing was commissioned by Pierre de Siebenthal (who was a wealthy amateur driver) from the Gachnang brothers.
The Angolan racing body at that time used to pay good starting money to encourage entries from Europe, and their Grand Prix was run to sports/GT regulations. The circuit was in Luanda.