In the race Chapman’s cars both suffered mechanical failure and were forced to retire, leaving Siffert to fight Amon for the duration of the race. Eventually, it was resolved by less than 5 seconds in Siffert’s favour, scoring him his first points-scoring F1 win, beating as he did World Champions past, present and future including Jackie Stewart, Denny Hulme and Jack Brabham, not to mention the likes of Jacky Ickx and Dan Gurney.
What no-one knew at the time is that it would be the last ever victory at the top level by a truly privateer team, a minnow among sharks, dusting the lot of them.
So, Mr Smith, the answer to your question is R7. It is neither the most successful nor the most famous of the Lotus 49s. But as someone who delights in the success of the underdog and who got to know Rob Walker just a little towards the end of his life and discovered first hand what a thoroughly charming man he was, I couldn’t call it any other way. To me, a car from a tiny customer team still being prepared as the big boys took to the track yet which nevertheless managed to humble the lot of them is the ultimate Formula 1 fairy tale. And thanks to Jo Siffert, Rob Walker Racing and Lotus 49B chassis R7, on July 20th,1968, the dream came true. If you want to pay your respects, it’s in the NEC right now, with every one of its surviving brethren.