1931 Norton CS1. 500ccc OHCThis lovely Norton CS1 was despatched from the works on the 11th of December 1930 and must be one of the last CS1s to sport the rare three stay craddle frame. The CS1 has confirmed matching numbers for frame and engine. The engine number is also stamped on the base of the cylinder, which Norton did in the 1920 1930s, so again a matching unit. The Norton is still on the same registration number as it was issued with in early 1931 and has had just 5