It is stamped on both sides 3692998 Erector Link Wrench. 39.5" long, 10" wide, 5" jaw opening, 1" thick and weighs approximately 11 pounds.
I really am hoping some of you all can help me on this. Where it might of been manufactured, use, year, and anything else. I basically found it at an estate sale by Pismo Beach, CA on a vast property that had a multitude of buildings and trash. The sellers didn't know anything about the history of it.