Was just gifted a model 99 that was basically in the attic, forgotten, for about twenty years. It's in very good shape and just needing a good cleaning. It has a Williams 'peep' rear sight mounted on the receiver. I'm looking to replace the sight with an original buckhorn style rear blade. Any help locating a source will be appreciated. I'll be hitting the range this weekend to see just how well we get along. Much thanks.