This spring is the return spring fitted to the rear brake arm on pressed steel brake plates (almost universally fitted on Nortons from the 1930's to the 1960's.
As with the springs above, a good quality original was used as a pattern.
We also sell this spring in chrome plated form - Item 0388, but if you wish to just paint the spring or get it dull nickel plated, then this listing offers the spring in bare metal form.
Note: This particular spring has a slight kink on the end that fits on the brake arm - as most brake arms had a similar outward kink. However, on some models the brake arm did not have a kink, and on this unplated version of the spring it is possible to carefully tweak the kinked part of the spring so it will fit the straight type brake arm