Short answer: A fake IW371407 gives itself away in four places: the subdial layout, the caseback engraving, the movement finish, and the price. The genuine IWC Portuguese Chronograph 3714 family uses a 40.9 mm steel case, two subdials with no date window, and a decorated caliber 79350 movement. If any of those details are wrong, the watch is not what the seller claims.

What Is the IW371407?

The IW371407 belongs to the IWC Portuguese Chronograph reference 3714 line, a stainless steel automatic chronograph with two registers. The family launched in the late 1990s and became one of IWC's most recognizable designs. References inside the 3714 range differ by dial color, hands, and numerals, so dial configuration is the fastest way to tell whether a case and dial belong together.

How Do You Spot a Fake IW371407?

Start with the dial layout. A real Portuguese Chronograph has a small seconds subdial at 9 o'clock and a chronograph minute counter at 12 o'clock, and it has no date window. Replicas built on generic Valjoux clones often shift the subdials, add a date at 3 or 6, or print the dial text with the wrong spacing. If a date aperture is present, the watch is not a faithful 3714.

Dial and Printing Checks

• Numerals are applied metal, not printed, and sit above the dial surface with crisp edges.
• The "International Watch Co." and "Schaffhausen" print is fine and sharp under a loupe, with no ink bleed.
• Subdial rings sit flat and line up with the surrounding dial printing.
• The chronograph seconds hand resets back to 12 with no drift.

Case, Crystal, and Weight Checks

The genuine case measures about 40.9 mm across, and the sapphire crystal carries an anti-reflective coating that shifts color when you tilt the watch. Replicas often run thicker and heavier, and their crystals lack that coating or show a strong blue tint. The crown and pushers should move with a firm, even action rather than a gritty or loose one.

Movement Checks

IWC caliber 79350 is a modified Valjoux 7750 automatic chronograph with a power reserve in the 44-hour range. The caseback on most 3714 examples is solid, so the movement can only be checked by opening the watch. Undecorated clones, wrong rotor engravings, and rough bridge finishing are common in replicas.

Caseback and Reference Number Checks

Engravings on the caseback should be crisp, deep, and consistent in font weight, covering the reference number, case number, and water resistance rating. Replicas often use shallow laser etching, or they engrave a reference that does not match the dial and hands. Cross-check the reference number against the dial variant before you pay.

Price and Seller Checks

Pre-owned IWC Portuguese Chronograph watches trade between roughly $4,000 and $7,000 in US dollars, with condition, box, and papers driving the spread. A steel 3714 offered for a few hundred dollars is a replica. A watch priced far below market with a rushed story is often a franken build, so ask for the invoice, service records, and a movement photo first.

Does a Fake IW371407 Ever Pass as Real?

High-end replicas can look convincing in photos, and some use real Valjoux base movements, so a visual check alone is not enough. A watchmaker can verify the movement finish, case construction, and crystal coating in minutes. For any purchase above a few hundred dollars, budget for that inspection.

What If the Watch Is Genuine but Has Fake Parts?

Franken watches mix a genuine case or movement with replica dials, hands, or buckles. The tell is a mismatch between the dial variant and the reference number engraved on the caseback. Buy from a seller who will document the movement and accept a return after inspection.

FAQ

How much does a real IW371407 cost?

Expect about $4,000 to $7,000 for a pre-owned example with box and papers. Condition and dial variant drive the spread, and replicas sell for a fraction of that.

Does the IW371407 have a date?

No. The Portuguese Chronograph 3714 is a two-register chronograph with no date window, so any date aperture points to a fake or a different model.

What movement is in the IW371407?

IWC caliber 79350, a modified Valjoux 7750 automatic chronograph. It drives the small seconds at 9 o'clock and the chronograph minute counter at 12 o'clock.

Can I authenticate an IW371407 by serial number?

IWC does not publish a public database that maps serial numbers to models, so authentication rests on caseback engravings, dial details, and inspection by a watchmaker or an IWC service center. Auction records and dealer listings help confirm that a reference and dial combination exists.