The pattern sheet was drawn by the famous Wisconsin stock maker Alvin Linden. Linden practiced his craft in a simple shack on the family farm near me in central Wisconsin. He wrote with a very colorful style, articles for the American Rifleman magazine. In 1941 Mr. Linden produced three soft bound booklets on stock making, in letting and finishing. They were published by Samworth Books. The pattern sheets were in a pocket in each volume. Linden died before The forth and final volume on checkering was completed.

The holy grail of Krag Sporters would be an Alvin Linden stocked example. He never signed his work so impossible to verify. The checkering (checking as he called it) is legendary. 

The pattern sheet you show was pirated, copied and sold by a Michigan Gun Shop.