Just found this old Gruen ladies movement in my dad's (retired watchmaker) old stock. Anyone know anything about it? Can't find anything in doing research. I think the face is beautiful with octagonal shape and engraving. The writing says" 15 Jewels, 4 adj., Gruen Guild. The hands are a shimmery blue/green color, but of course, I don't know if they're original. The dial only says "Gruen" on the front. It also appears to be working, but the hands don't move. Thanks so much.