Has anyone installed a scope mount on their Krieghoff? If so, what kind? These guns have the two rear screw holes already in the rib, so installing a rear base of any type, and a front base for a pivot or Warne type would not be hard. If you installed one, did it change regulation? I have a 450-400 and am thinking about a scope. I know, Doubles don't get scopes. But I am thinking about it anyway.