Gruen | Ref. 401-420Gruen, established in 1894, was a leading American watchmaker recognized for its inventive designs and Swiss made movements. By the 1940s, Gruens catalog featured a wide range of elegant wristwatches, many with distinctive case shapes and lugs, and reliable manual wind calibers. The 401 420 reference family is representative of this era, often featuring slim, plated base metal cases, full numeral dials for easy reading, and unique lug designs that