There is an KYMCO item which is to be mounted at models without parking brake (restitutes Stigs asparagus bands).
It comes with an INOX bolt and two different brass distancers.
Fixed instead of the original brake levers bolt, it holds spring activated the lever in back position, you touch the lever, spring releases, brake is off.
EDIT: Mounted today, works fine, even its visually not a pleasing solution (pls see pics).
@Neil, have to wait, was a promo until series.