Similar to older form of German thimble maker marks. Center of star may be broken circle, or letter "C", "G" or "U". No interior markings here. Repeated Art-deco design around base. [Not actually the central dome over the Coburg Hotel in London, but Hitchcock would be pleased about the reference to his own cameo appearances.] TIA
Believe that's Gebrüder Gabler, or later, Greif, but perhaps not with a 6-point star? Been quite a while since I've dealt with thimbles, but seem to recall the use of 925 fineness rather than 800 on German thimbles usually indicates later production. Looks like there are remnants of enamel?