Can anyone identify this cable, which came with stuff believed to be late Norton, Commando era. It's new, unused. Distinguishing feature is the rubber boot mid cable, which conceals a spring. No switch, just a spring, but a stiff spring, like a valve spring. Half inch ID, 2 1/8" long, and won't compress at all under finger pressure. There's also a natty little rubber concertina cover for the presumed pedal end. Having the adjuster mid-cable is unusual, too