Almost entirely interchangeable with the Curvex 440 movement.
Is the "Precision" 17 jewel version of the Veri-Thin 430 family of movements consisting of 430, 431, 435
Gruen states that the 440 Curvex uses the same parts as the 430 except for Ratchet Wheel, however that's a gross summary. Closer examination shows these differences
- The ratchet wheel's text (mechanically they are the same)
- The pillar plate has differing caliber stamps
- The pillar plate on the 440 is "curved"
- The ratchet bridge with the serial number
- The train bridge has different text and design but mechanically the same