The Model 17 replaced the standard Model 16 around 1901 and maintained a similar appearance to the previous model with a solid 3/4 top plate. Material Catalogs provide the following serial blocks for Model 16 production: 420,001-500,000 and 900,001-950,000. However, because these blocks were designated prior to publication in 1904, it does not include all Model 17 movements. The primary modification from the previous Model 16 design is the upgrade to Breguet hairsprings instead of flat. These can be easily identified by the location of the hairspring stud appearing to touch to perimeter of the regulator arm retention ring (flat hairsprings are mounted further from the retention ring). Other part upgrades include jewels, fourth wheel/pinion, regulator , and yoke.
A special note in the material catalogs indicate movements with serials 456,001-457,000 were fitted with divided top plates like the Model 14 and feature 16 jewels. Some other parts within this block are also different than the standard Model 17.
