I have a pair of M frame SI. I ordered a new lens and the nose piece does not interchange. The original lens had a "C" where the nose piece snapped into and the new lens has only an indentation I'll call it so the orignal nose piece can't snap in or stay attached to the lens in any way. I don't mind purchasing a new nose piece IF they are available and IF I can get one that will be compatible with this new style lens. Any help is appreciated.