I have this Williams Superrench with the Ribbed Shank. I think they made the ribbed type from 1952 - 1959. The model number stamped on it is 1731A. It's an open end 7/8" X 3/4". I've searched far and wide, found several 1731A's, but no 7/8" X 3/4" with the ribbed shank. :headscrat Do I have a...