The single most decisive check on a suspect IW371462 is the movement, not the dial. Dial printing can be copied with a good printer and a steady hand; finishing an IWC chronograph calibre to factory standard is a much harder problem. This guide ranks five checkpoints by how reliably they separate a genuine Portugieser Chronograph from a fake: movement and chronograph feel first, then caseback engraving, dial and subdial detail, crystal and hands, and finally papers and provenance. Each section lists what the checkpoint catches and where it fails.

What IW371462 should be before you judge it

The 3714 series is the Portugieser Chronograph: a stainless steel case around 40.9 mm across and roughly 12.3 mm thick, with a bicompax layout, running seconds at 6 o'clock, a 30-minute counter at 12, and a date window at 3. Earlier examples used the calibre 79350, a Valjoux 7750 base reworked by IWC; later production moved to the in-house calibre 69355. The trailing digits of a 3714 reference point to a specific dial and case combination, so confirm what IW371462 should look like against an IWC catalogue entry, a service invoice, or a dealer listing, rather than a single photo pulled from a forum thread.

Checkpoint 1: Movement and chronograph feel (top pick)

Open the caseback, or have a watchmaker do it. Look at rotor engraving depth, screw colour, and the shape of the bridges, then run the chronograph.

  • What it catches: Decorated 7750 copies with shallow laser engraving; screws that are painted blue rather than heat-blued; glued-on decorative plates that hide a generic movement underneath; a chronograph reset that drifts instead of snapping the centre seconds hand straight back to 12.
  • Where it fails: A well-finished clone movement photographed at an angle in poor light can pass a quick eyeball test. You need magnification and a pusher feel comparison against a known genuine watch.

Checkpoint 2: Caseback engraving and serial placement

Reference numbers, the IWC script, and the Probus Scafusia wording are cut or laser-marked to a specific depth on genuine cases. Fakes tend to show shallow, rounded lettering with inconsistent spacing between characters.

  • What it catches: Engraving that sits flat on the surface, mismatched fonts between the reference and the serial, and serial ranges that do not match the production era of the reference.
  • Where it fails: Genuine cases get polished during service, which softens engraving. Compare against a service record before you call a watch fake on this alone.

Checkpoint 3: Dial printing, subdials, and date font

Look at the wordmark and the Schaffhausen line under a loupe. Genuine printing has clean edges, even stroke weight, and consistent spacing. The subdial rings should show fine concentric snailing, and the date numerals should match the factory font, not a generic typeface.

  • Strengths: Cheap for you to check, needs no tools beyond a loupe, and catches most low-tier replicas in seconds.
  • Limits: High-end replicas print dials well. Bleeding edges and fuzzy text are a strong sign of a fake, but clean printing is not proof of a genuine watch.

Checkpoint 4: Crystal, hands, and crown

The sapphire crystal on this family carries anti-reflective treatment that produces a faint blue or purple cast at certain angles. Leaf-shaped hands should reach the minute track without overrunning it, and the crown should carry a crisp logo and turn with defined threads.

  • What it catches: Single-sided AR coating, hands cut a fraction short or long, crowns with soft knurling, and case finishing where the brushed and polished transitions blur together.
  • Where it fails: Crystal tint varies with lighting and camera. Use it as a supporting signal, never as your main evidence.

Checkpoint 5: Papers, box, and provenance

Receipts, warranty cards, and service paperwork matter more than the box. A serial number that appears in an IWC service record is worth more than any photograph.

  • What it catches: Sellers who avoid service history questions, cards with mismatched serials, and prices far below the market for the reference.
  • Where it fails: Genuine watches get sold without papers all the time, so missing documents prove nothing on their own.

How to combine the checkpoints

For a private sale, run the dial, crystal, and caseback checks yourself, then insist on a movement inspection before money changes hands; that order saves you the cost of opening a watch you were never going to buy. For an online listing, ask for a timestamped photo of the caseback serial and a short video of the chronograph reset, and treat a refusal as a red flag. If you are buying a replica knowingly, understand what you are getting: the case and dial may look close, but pusher feel, movement finishing, and long-term serviceability are where the gap shows. Passing a replica off as genuine is fraud in most markets, whatever the watch looks like on the wrist.