The Alloy Artifacts' Craftsman page says ca. 1947 with an image and this text:
Fig. 26 shows a pair of Craftsman waterpump pliers with a distinctive 4-position adjustment mechanism. The pliers are stamped with the Craftsman double-line logo on the handle, with "Forged in U.S.A." and an N-Square manufacturer's code on the reverse.
The overall length is 9.9 inches fully extended, and the finish is chrome plating.
The adjustment mechanism uses a tabbed pivot post operating in slotted holes. To change the setting, the handles are opened wide to align the tabs with the slots, allowing the handles to be separated and then reinserted in the desired hole.
http://home.comcast.net/~alloy-artifacts/craftsman-maker-v.html#pliers