I seen this a week ago in a junk shop and just today decided I need it.  It is the older version without the release bar.  I only had to oil it a little to get it ready for the home "classics" box.  These semi-retired tools are the ones that do all my little jobs in the house.

It has a 1942 patent on it and a "other pat. pend." marking.  That would put it into the 1940's to early 50's range.  It is a Petersen Mfg. Co.  made tool out of DeWitt, Nebraska.  No notable wear in the pins or joints, sweet.

I paid a whole 6 bucks for it.  I'm going to leave the patina and just use it as is. 

My pics are bad but I hope they show something.  Never buy a hello kitty webcam, ever.

I found one just like it yesterday at a garage sale here.
Works perfectly, and like it better than the newer ones, with a separate release lever.
Lots of this type are used to hold metal pieces together in order to weld them.
I grind off the weld splatter.

I think it is a wrench, as any pair of pliers are.  Pliers seem to represent an offshoot of wrenchdom, but still have applications similar to wrenches, e.g. grasping a piece of metal and turning it or bending it in ways bare fingers cannot.