I have been a working machinist for the last 25 years and have never used this tool and do not ever see using it in the future.
5" Starrett vernier caliper from the 40's/50's by Starrett with A. Worrall engraved on it along with L.S. Starrett Co., I suspect that this was some sort of employee award or gift.
Original wood box lined with velvet, pristine condition aside from the fact that my Grandfather engraved his name on everything that he owned.
I also have no idea what or whom A. Worrall was or is, someone here may know the answer. It is extremely well made as are all Starrett tools yet so small that the scale is unreadable without Superman's eyes, this may be a result of my vision failing this late in the game (-: