Short answer

A fake IW371419 fails on four points: case thickness, subdial layout, dial printing, and the chronograph movement. The genuine watch is an IWC Portugieser Chronograph from the 3714 reference family. That means a 40.9 mm steel case, two subdials, no date aperture, and calibre 79350, a modified Valjoux 7750. A counterfeit with a date window, a 42 mm case, or a quartz movement is not that watch.

What the reference covers

IWC built the Portugieser Chronograph reference 3714 from 1998 to about 2020. The family holds many dial variants under IW3714xx numbers, and IW371419 sits inside that range. IWC does not run a public serial number lookup. Dial colour, hand shape, and caseback text for one exact number should come from IWC service or a dealer with the archive record. A listing that shows stock photos only is unverified.

Case and crystal

  • Diameter 40.9 mm, thickness 12.3 mm, lug width 20 mm, water resistance 30 m.
  • Sapphire crystal with anti-reflective coating on both faces. It shows a blue tint at an angle.
  • Case in steel or gold, with polished bezel and brushed case sides.

Fake cases run 1 mm to 2 mm thicker and weigh more than the real thing. Lugs feel sharp at the edges. The crystal reflects more light and shows no colour shift.

Dial

Two subdials: running seconds at 6 o'clock, chronograph minutes at 12. No date. Applied numerals, leaf (feuille) hands, and a railroad minute track. On a fake, the numerals sit flat or stand too tall. The word SCHAFFHAUSEN is too wide or too bold. Subdial rings are printed on a flat surface instead of a recessed disc. The hands are thick at the base.

Watch the small seconds hand. Calibre 79350 runs at 28,800 vph, which is 8 beats per second. The hand moves in 8 small steps. A quartz fake ticks once per second.

Movement and pushers

Calibre 79350: automatic, 31 jewels, 44 hour power reserve, 28,800 vph. The base is the Valjoux 7750, a cam and lever chronograph. Pusher feel is firm with short travel and a clear click. Fake chronographs need a hard push, or the start button does nothing on the first press. The rotor on the real movement spins with a slight wobble on the wrist.

Most steel 3714 examples have a solid caseback engraved with the reference and serial. Some later or special editions use a sapphire display back. Fakes show shallow laser etching, wrong font, or a display back over a generic movement with no IWC markings.

Papers, price, and seller

Pre-owned steel 3714 chronographs sell for about $3,500 to $7,000, based on condition, box, and papers. Gold versions run higher. A listing at $400 is not a bargain. Ask for the box, the warranty card or an extract from the archives, service receipts, and a sharp photo of the caseback serial. Call IWC service with the serial. If the seller refuses, stop.

Quick checklist

  • 40.9 mm wide, 12.3 mm thick. Thicker and heavier means fake.
  • No date window. A date at 3 or 6 rules out the 3714 layout.
  • Small seconds at 6, chronograph minutes at 12.
  • Applied numerals with polished edges.
  • 8 beats per second on the small seconds hand.
  • Deep engraved caseback, even font.
  • Serial confirmed by IWC service.