Stamped "PAT'D APRIL ... 68" around a crisp as day "STAR TOOL CO" logo. Beautiful rosewood. Fine overall condition noting a sliver off the groove that the cam lock action works on, but doesn't impair use. Very clear gradations up to 16ths of a inch. Seldom seen. Still glossy after all these years!
More information on this patent can be found via datamp.org who describes this as "One of the most brilliant designs in tool history. "