Promo,your k98 is a double-code produced jointly by Gustloff and Steyr-Daimler-Punch in 1944.the single rune is there because to my knowledge it was reworked for or under SS supervision.theres a book that i get much info from you may already know of.the book is called Backbone of the Wehrmacht which is still available.im no expert but hope i was of some help to you.your rifle i think is very rare and i wouldnt let it get away.always keep it in its original configuration you will be glad later.