Emilio De Villota at speed in his Lotus 78 at Brands Hatch leading the LEC of David Purley.
This is a race from the 1979 Aurora AFX British F1 series - Villota went on to win the series in 1980(driving a Williams).
I think the Villota car is the 1977 Belgian GP winning chassis driven then by Nillson.
The fact Purley is on shot is interesting as this was his first race after the near-fatal shunt he endured at the 1977 British GP in which his surviving of an enormous impact gained and entry in the Guiness Book Of Records for the highest G-loading ever survived. He suffered terrible leg injuries and worked amazingly hard to make a comeback, racing the outdated LEC at Brands and then a works Shadow DN9B in later races before retiring from the sport, having proved his point, to take up stunt flying - at which he was sadly killed in 1984.