Top pick: the column-wheel build
Start with the top tier. A fake IW371784 built on a copy of the IWC 69355 column-wheel caliber is the version to compare against the real watch. It carries the correct subdial layout: running seconds at 6, chronograph minutes at 12. Pusher feel is crisp. The caseback shows a decorated movement. Case height sits within about 0.5mm of the genuine watch.
Fake IWC Portugieser IW371784: How to Judge a Replica Before You Buy
Every tier below that one trades a trait for price. The mid tier keeps the dial and case shape and drops the column wheel. The low tier copies the silhouette and nothing else.
What the genuine IW371784 does
The reference is a Portugieser chronograph. Slim bezel, leaf hands, applied markers at 12 and 6, two subdials, no date, sapphire display back, alligator strap on a folding clasp. Current production uses the in-house 69355, a column-wheel chronograph with a vertical clutch. Earlier Portugieser chronographs used caliber 79350, a Valjoux 7750 base.
IWC does not publish a public parts list for the reference. Confirm caliber, case height and strap material against the seller's own spec sheet before you pay.
Fake IW371784 compared to genuine, by tier
- Tier A, about $450 to $700. Clone 69355 with column wheel. Case height within 0.5mm of the real watch. Short pusher travel. Correct dial print weight and applied markers. Signed rotor and clasp.
- Tier B, about $250 to $380. Asian 7750 with a gear module that moves running seconds to 6. Case runs 1mm to 1.5mm thick. Pusher travel is longer. Dial print is heavier. Mineral back glass on some builds.
- Tier C, about $120 to $200. Quartz or a stock 7750. The 6 subdial is fixed or runs as a 24-hour hand. Bezel profile is rounded. Solid steel back.
Side-by-side tells
- Hands. Genuine leaf hands carry a polished bevel. Replica hands are flat stamped.
- Subdial axis. Genuine subdials sit on the 12 to 6 line. Low-tier 7750 builds shift the top subdial a fraction off center.
- Crown. Genuine has deep relief on the signed crown. Replicas are shallow.
- Dial print. Genuine print is thin and raised. Tier C print is flat and heavy.
- Strap. Genuine is alligator with a signed folding clasp. Most replicas ship embossed calf.
- Caseback ring. Genuine engraving is soft and shallow. Replica engraving is deeper and wider.
Reliability notes
The 7750 base is a known workhorse and any watchmaker can service it. The 6 o'clock seconds module adds drag and parts. Column-wheel copies run well when clean and are harder to source parts for. Budget for one service in the first two years on any tier B or tier A build.
Check before you pay
- Ask for a macro photo of the subdial at 6 and the crown.
- Ask which movement: 7750, modified 7750, or column wheel.
- Ask for the measured case height, not the catalog number.
- Confirm clasp signing and strap material in writing.
- Confirm a return window of at least 7 days.
Bottom line
The top-tier column-wheel build is the version that holds up next to the real watch. Below $400 expect a thicker case, a 7750 drivetrain and heavier print. Buy from a seller who names the movement and accepts returns.