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.