Gruen Precision 18k gold from 1930s

Gruen "Precision" from circa 1930, featuring an 18k white gold case measuring 37 x 22 mm, with an engraved case band and a fluted crown. The silvered sector dial displays black lacquered Arabic numerals at 12, 3, and 9, partial baton indexes, blued hands, and a subsidiary seconds dial. It is powered by a manually wound shaped movement signed Gruen Precision.