Bring up the google front page, and click on the videos search button. Then, type in "how wrenches are made", and you will see not only how wrenches are made, but pliers, sockets, etc. Very Interesting!!!!. As far as the old stamp cut method, I have seen shears that would cut thru 3/8" steel like butter, so I imagine the old stamed wrenches were cut like a cookie cutter, with a series of die cutters, but I could not find an old video of it.
Wayne