Those things are collector items, some Triumph riders have them just to have them, same as the Davida.

You may be better off at this point in time purchasing a good black open face helmet and doing the decal route, which is old school. The other route would be to start emailing Triumph dealerships, every dealership I've visited had them at one time. Good luck.

Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats. H. L. Mencken