A fake IW371487 is a counterfeit of an IWC Portugieser Chronograph. The reference sits in the 3714 family. The genuine watch has a steel case measuring 40.9 mm across, 12.3 mm thick, and rated to 30 m. It runs the IWC caliber 79350, a Valjoux 7750 base beating at 28,800 vph with a 44 hour power reserve. Fakes copy the outline. They miss the four checks below.
What the reference covers
The Portugieser Chronograph uses two registers: a 30 minute counter at 12 o'clock and running seconds at 6. Records for IW371487 are thin. IWC's own archive and authorized dealer listings confirm dial color, strap, and production year for a given serial number. Claimed specs in a marketplace listing prove nothing.
Case and caseback
- Measure the case without the crown. Genuine width is 40.9 mm. Many replicas run 40 mm or 42 mm.
- Caseback text is engraved, not printed. Reference number, serial number, and Schaffhausen sit in the factory font at even depth.
- The sapphire crystal sits flush with the bezel. Counterfeits often carry domed mineral glass with a blue edge tint.
- Pushers have a firm start and a sharp return. Loose, gritty pushers point to a low grade movement.
Dial and hands
Dial print holds up at 10x magnification. Fake dials show thick paint, uneven index spacing, and a date aperture cut off center. Subdial hands on the real piece are thin and reach the track. The chronograph seconds hand resets to zero and stays at zero.
Movement
Open the caseback. Caliber 79350 runs at 28,800 vph, which is 8 beats per second. A movement running at 21,600 vph, 6 beats per second, is a clone. The rotor and bridges carry IWC engraving. Côtes de Genève finishing on a fake is shallow and uneven.
What "first copy" means
Sellers use first copy, AAA, and super clone for different grades. Price bands overlap and labels vary by seller. No grade equals a genuine IWC. Buyers who want the real reference should buy from an authorized dealer or a seller with a service history.
Price signals
A used steel Portugieser Chronograph trades in the thousands of US dollars. Listings under 500 USD are not genuine. Serial numbers can be checked through an IWC boutique or an authorized service center.
Limits of a photo check
Photos hide weight, finishing, and movement. A case can be copied to 0.1 mm and still feel wrong on the wrist. A watchmaker with the caseback off settles the question.