Have to say, I've never in my 59 years of life, ever seen one. Have seen the typical Williams or Armstrong ones, but never seen one of these. Looking at how it is built, it may pre-date the Williams/Armstrong design. I'm no antique tool expert, my guess says it dates around very early 1900's.
Have you Googled Hawthorne Tool Company and see what comes up? Any patent dates stamped on the tool?