From Norton Owners Club

Although the first Commando appeared in late 1967, it was not called the Fastback until other Commando models appeared. The early Commandos proved to have weak frames and the design was soon modified with an extra bracing tube to the headstock which solved the problem. A restyling exercise in 1970 saw the Fastback Mk.ll with upswept exhausts, reverse cone pipes replacing the Atlas type ones used up to that point. Only four months later, the Mk.lll arrived on the scene, with several changes including modified centre and side stands and a wider section front tyre. The Mk.lV in January 1972 brought a front disc brake and direction indicators. Production ceased in early 1973. The Fastback was never offered for sale with the 828cc engine.

1970 Model


So it's probably a 1970 with a 1972 or later disc brake

Steelheart- '03 Speedmaster Black/Yellow The Hayabusa Killa 16" Shorties/140 mains/Airbox drilled Procom CDI "There is no cure for Celibacy. But we can treat the symptoms."