That red No. 16 car is a Porsche Special built up on a wrecked Spyder - RSK I think - by Pierre de Siebenthal with some help from Georges Gachnang of Cegga fame and bodied by Drogo. They usually just called it Porsche, but sometimes also Porsche Prototype or Cegga-Porsche. It started its career with a 1600/4, then moved up to 1700 cc, and finally got a 19916 engine. Its driver at the occasion might be Antonio Peixinho, but that's just a guess.
Pius Zünd's Lotus 30 cannot be the AC Angola car, as suggested on Kirk's homepage. It was bought new by Karl Foitek via Lotus Suisse and delivered directly to Vienna for an airfield race in spring 1965. After very few practice laps, Foitek was stopped by - guess what? - a suspension failure. He was fed up with the car and sold it on the spot to Fritz Baumann. Baumann used it only a few times before handing it over to Pius Zünd/Ecurie Filipinetti. The ownership at that time isn't clear to me. Then came that Angola race with another suspension failure.
So far, all this is written exactly as Karl Foitek told me.
Then, the car must have returned to Switzerland and sold to Franco Sbarro who transformed it into a roadgoing Coupé. It still exists today and is still road registered.
Kirk, if you send me your mail address by PM, I can send you pictures, but I am too stupid to do it directly here.