This is the Motor road-test car bought by Ian Penrose in 1966, stripped, then rebuilt from the ground up, painted Rolls Royce Regal Red and trimmed with black upholstery and red carpets.
"Combining good looks with modest wind resistance, the Doretti body is metal framed and combines with the reinforced tubular chassis to make this an exceptionally rigid open car. Conversion from open to closed trim is rapid, even without leaving the car." ... The Motor