John, it sounds like you might want a clunky bike helmet instead. These (for example Bell) cost about half as much as a climbing helmet but weigh significantly more than a Meteor or Elios (mot a problem since you will only be wearing it cleaning the route, right?).
BE CAREFUL. We do not want you or Donini or anyone else killed in this endeavor. Be sure to give us the details once this undoubtedly awesome route is in the books and done with.