The story of Gruen Curvex is detailed by Mr. Paul Schliesser at his beautifully designed website:
http://www.pixelp.com/gruen/1929.html

10K  Yellow Gold Filled Case. Silver Original Dial. 17 Jewel Manual Wind. Cal. 370.

Yellow Gold Hands and Arabic Numerals. Original Signed Crown. Plastic Crystal. 42x22.5mm Case.

Completely Serviced by Mr. David Hornstein in February, 2006.