Short answer
IW371765 does not appear in IWC's published reference lists. The 3717 family covers IW371701, IW371702 and IW371704, the Pilot's Chronograph Automatic sold from 2006 to 2012. A watch sold to you as IW371765 is a replica, a case with a wrong number, or a listing typed from memory. Ask for an IWC service record or an extract from the archives before money changes hands.
3717 specs to compare against
- Case: steel, 42 mm, about 14.5 mm thick
- Movement: cal. 79320, a modified Valjoux 7750, 28,800 vph, 25 jewels, 44-hour power reserve
- Dial: day and date at 3, running seconds at 9, 30-minute counter at 12, 12-hour counter at 6
- Crystal: sapphire, anti-reflective coating on both faces
- Water resistance: 60 m. Soft-iron inner case
- Caseback: solid steel on this generation
Checks
1. Reference and serial engraving
IWC stamps the reference and the serial number between the lugs. At 10x magnification the digits have sharp edges. Numbers on replicas look sandblasted, sit shallow, or use a font with a wrong 7. The inside of a genuine caseback carries the maker's mark.
2. Caseback
The 3717 has a solid steel back. A watch with a glass back and a decorated rotor is a different reference. Treat a printed number on the outside of the back that does not match the engraving between the lugs as a warning sign.
3. Movement behavior
Wind the crown and set the day and date. Cal. 79320 changes them with a firm click. The chronograph pushers have short travel and the hand resets to zero in one push. Chinese 7750 clones feel loose at the pushers, and the chrono seconds hand drifts on reset. A quartz movement gives the answer at once: the seconds hand ticks one step per second.
4. Dial and hands
The 3717 shows the day and the date at 3. Check the index alignment with the subdials and the print of "Schaffhausen" under the logo. Replica dials show thick print, uneven lume, and a minute track that misses the markers.
5. Price
Dealer listings for used steel 3717 watches sit in the low four figures in USD. Offers near $200 to $500 describe a replica, not a discounted genuine watch. Listings with "no box, no papers, price negotiable" are replica listings until proven otherwise.
Steps before you buy
- Ask for a photo of the engraving between the lugs at 10x.
- Ask for a timegrapher photo: rate, amplitude and beat error at 28,800 vph.
- Request an IWC service invoice or a case check from IWC customer service in Schaffhausen.
- Open the caseback with a watchmaker. Compare rotor engraving, balance assembly and jewel settings.
- Pay with a method that allows a chargeback. Skip bank transfer.
What is not known
IWC does not publish a searchable archive of every reference number. If a seller shows a number outside the published 3717 list, treat the watch as unverified and confirm it with IWC before you make an offer.