This showed up on the Railroadiana Online Q&A Board. You can read the question and the answer provided here. It is question #1978. Is the answer correct?

http://www.railroadiana.org/pgQB.php

I got only one answer from ICON, as follows: "Working for New England Tel and Tel Co. as a linemen this was what a we knew as line "linemen wrench" Klein Bell System Type Wrench "

On the railroadiana board the question got a lot more answers. Follow the above link and go to question 1978. Two writers were adament that this is not a lineman's wrench. Other answers include a locomotive tool, a Bridge and Building tool, and a bung wrench.