Replica IW371778: Short Answer

IW371778 falls in the IWC Portugieser Chronograph reference family. The line runs a 41 mm case, a two-register dial with running seconds at 6 o'clock, and chronograph minutes at 12 o'clock. Replicas of this reference sell for about $250 to $500. Most run an Asia 7750 chronograph movement. The genuine watch runs the 79350 (a Valjoux 7750 base) on older generations and the in-house 69355 on newer ones. No replica copies the 69355 finish.

Reference Basics

IWC reference numbers use the IW prefix. The first four digits mark the model family. The last two digits mark the dial, case metal, and strap variant. The current IWC catalog lists the Portugieser Chronograph under IW3716xx. Older catalogs list IW3714xx. I could not verify a public IWC catalog page for IW371778 itself, so treat the last two digits as a variant code and confirm dial color, case metal, and strap with the seller.

Genuine size: 41 mm across, about 12.3 mm thick on the 3714 generation, about 13.1 mm on the 3716 generation. Genuine crystal is sapphire with antireflective coating on both sides.

Movements in Replicas

The Asia 7750 is a Chinese copy of the ETA 7750. It is a cam-switching automatic chronograph, 28,800 vibrations per hour, about 44 to 48 hours of power reserve. The 79350 is a modified 7750, so the pusher layout and hand stack line up. That makes the older 3714 generation easier to copy than the 3716. On the 69355 generation, the movement architecture differs, and replica makers substitute a 7750-based unit. Expect a thicker case and a rotor that spins on wrist.

Dial and Case Checks

  • Subdial spacing: the 6 and 12 counters sit on a vertical line through the center. Any drift shows at the 12 counter.
  • Date window: on 3714 references the date sits at 3 o'clock. Check the numeral font against photos of the genuine dial.
  • Applied numerals: gold-tone, polished on the sides, flat on top.
  • Caseback engraving: depth and font weight. Laser etching looks shallow under a loupe.
  • Pusher feel: firm click, no side play. Loose pushers point to a low-grade 7750.
  • Crown: threads engage in two turns. Gritty threads strip over time.

Price Bands

$250 to $320 buys a basic Asia 7750 build with a mineral or low-grade sapphire crystal. $320 to $500 buys better case finishing, a sapphire crystal, and a closer dial print. Anything under $180 uses a quartz or a 21-jewel automatic without a working chronograph.

Before You Pay

  • Ask for a video of the chronograph start, stop, and reset.
  • Ask for a photo of the movement through the caseback or under a loupe.
  • Confirm the return window in writing.
  • Skip sellers who list "Swiss made" on a watch under $500.

Servicing: a watchmaker can regulate an Asia 7750 and replace gaskets. Parts for the 69355 are not available to independent shops, so a replica of that generation cannot be repaired to genuine spec.