I'm trying to find out the name of a children's horror story collection that I read in the US in the early 80s, which would put the publication date sometime in the 70s or possibly 60s. The story I have in mind is apparently a retelling of an old folk tale: a medieval kingdom is being ravaged by a werewolf, and a hunter is hired to capture or kill the monster. He meets the werewolf one night and in a struggle, severs the paw of the creature, which runs off. Picking up the paw, the hunter finds that it has transformed into a woman's hand. I believe the hand had a signet ring on it, which doesn't make logical sense, but in any event he goes to the castle where he discovers either the queen or princess in bed and missing her hand. I seem to recall a black and white drawing of the stricken woman lying in a castle bedroom.