In persuing watches by Gruen I got an interesting one. Info from NAWCC Bulletins: Gruen originated the Columbus grades 46,47,48 in 1888. Hunter and open face. 1889 ad shows this 46 cheapest at $40.with 15j but rated for r.r. service. It was only one made with the odd Gruen designed regulator. Shown in ad only with Nickel plates. Serial 97000+ is for 1889. So a good early uncommon 16 size U.S. Gruen example. However, this one not marked adjusted necessary for actual r.r. use.