I acquired twenty of the Williams advertising statues some eighteen years ago, NOS in original boxes (sold the last extra one a few months ago). Below is a scan of the instructions that came in the boxes.
Wrench measures .240 inches wide where it fits into the hands. So if you can come up with a Williams that wide it should fit.
(http://i222.photobucket.com/albums/dd3/buswrench/message-board/williams-adv-paperweight-insts.jpg)