Hello, I donīt want to rain on any parade, but I do know such a feature (as marked) only from modern, at least past WWII knives. During IIIR the daggers were rudely stuck on nails how countless hanger examples (often early RAD or such) do proof. Just my personal observation and opinion. Perhaps any of our collector friends can us show any other doubtless IIIR dagger with such a certain feature. Regards,
Herman V. and Mac 66, thank you very much for correcting me. I have not been aware of this feature for this period up to now. Again I have learned something! Regards,