✔ Correct Identification

• Manufacturer: IWC Schaffhausen

• Type: Pocket watch movement

• Serial Number: 403945

(Places production approximately 1915–1920)

• Movement Caliber:

This serial range corresponds to IWC Caliber 52/53 family
(the classic high-grade IWC pocket watch movement of the early 20th century).

✔ The bridges, gear layout, regulator design, and jewel settings match Cal. 52 / 53
✔ NOT modern calibers — this is an antique IWC pocket movement
✔ Beautifully finished with Geneva-style gilt plates

✔ Dial

• Dial brand: Guggenbühl Merian – Basel

This is a Swiss retailer-signed enamel dial, original to the watch.

• Dial condition:

• Enamel with classic Arabic numerals

• Small seconds at 6 o’clock

• Minor age marks as expected for a +100-year-old dial

• Original gold-tone hands included

✔ Measurements (from your photos)

• Dial diameter: ≈ 43.30 mm

• Movement diameter: ≈ 41.94 mm

Fully consistent with IWC Cal. 52/53 pocket watch movements.

✔ Crown

• Crown:

Original IWC 18k solid gold pocket crown
(fitted properly to the stem, correct early IWC style)

✔ Ready-to-use listing description

IWC pocket watch movement, serial 403945, fully serviced and running perfectly. Movement corresponds to IWC Caliber 52/53. Includes original enamel retailer-signed dial “Guggenbühl Merian Basel,” original hands, and original 18k IWC gold crown. Dial diameter ~43.30 mm, movement ~41.94 mm. Excellent functional condition, authentic early 20th century IWC craftsmanship.