Illinois 18 Size Very Early Mason Key Wind Open Face Pocket Watch. The watch is running well and keeping time.  The triple hinged case is in very good condition.  There are a few small, minor spots of tarnish.  The extra thick beveled glass crystal is in excellent condition, with no scratches or chips.  The key wind from the front and key set from the back gilt movement is in very good condition.  The dial is an original "Springfield Watch Co." dial that was only on very early movements before Illinois Watch Co. changed it within the first year of production or so.  The dial is in very good condition. The serial number on the movement is a very low #577, dating to early 1873. A key is included. Thank you.