Short answer
A fake IW371432 lives or dies on three things: the dial, the case thickness, and which movement sits inside. Good replicas get the 40.9mm case, the two-register layout, and the leaf hands close enough that you need a loupe to argue. Weak ones miss the thickness by a millimeter and a half, print the subdials flat, and put a stock Valjoux under a display back that should never have been there. Look at the dial first, the case second, the movement third, the price last.
What the reference actually is
IW371432 belongs to the IW3714 Portugieser Chronograph family. Stainless steel, about 40.9mm across and 12.3mm thick, sapphire crystal, 30m water resistance, two subdials (chronograph minutes at 12, running seconds at 6) and a date at 3. Earlier examples run the 79350, a modified Valjoux 7750 base. Later ones use the in-house 69355 with a column wheel and roughly 46 hours of reserve, and that one comes with a display caseback.
That single fact decides half your inspection. A solid engraved back on a watch claiming to be a 69355 example is wrong. A display back showing a plain 7750 rotor on a 79350-era reference is also wrong. Know the era before you judge the watch.
The three replica tiers
- Budget. Quartz or a rough 7750, printed markers instead of applied ones, hollow end links, a date window with a visible step around the aperture. It reads as a Portugieser from two feet and as a fake from one.
- Mid. Asian 7750 with decorated bridges, applied numerals, decent printing, thickness usually 13.5mm or more. Most of what you will find sits here.
- Top. A clone of the 69355 architecture, correct case thickness, properly faceted numerals, concentric finishing on the subdials, and a caseback that matches the reference era. This is where the money goes and where the argument about value starts.
Dial and hands, where fakes slip
The Portugieser dial is mostly empty space, which is unforgiving. Any flaw has room to show. I check these in order:
- Applied numerals. Real ones are faceted and diamond polished, so the top plane flashes and the sides go dark as you tilt the watch. Stamped replicas look uniformly grey.
- Leaf hands. The taper should be even and the tips should come to a clean point. Bent or blunted tips show up on cheap examples.
- Subdial finishing. Snail or azurage texture should catch light in rings. Flat printed circles are the most common shortcut.
- Print weight. The name and the scale should be thin and sharp. Heavy ink that spreads at the edges is a tell.
- Date aperture. Clean cut edges, no white core showing through, and the disc should sit close to the dial.
Subdial size relative to the numerals matters more than exact spacing. A 7750 and the 69355 both place registers at 12 and 6, so position is rarely the giveaway. Proportion is.
Case, thickness, and caseback
Measure it. A 7750-based chronograph module adds height, and plenty of replicas come in at 13.5mm to 14mm against the real 12.3mm. That difference changes how the watch sits under a cuff and how the lugs look from the side. Lug shape, the curve of the caseband, and the polish on the bezel edge are the next things I look at, since replica cases often have a slightly softer transition between brushed and polished surfaces.
Caseback engraving should be deep and crisp, not laser-shallow. On display versions, the movement should look like the movement it claims to be, not a decorated plate with a generic rotor.
Movement behavior
Pusher feel separates the tiers fast. A column wheel chronograph starts and stops with a light, clean click. A 7750 feels heavier and the chrono seconds hand can jump on start. Reset should snap back to zero in one motion with no wobble. Wind it and listen: a dry, grinding rotor is a service bill waiting to happen. Ask about the power reserve, then check it. Roughly 44 hours for a 7750, roughly 46 for the 69355.
Strap and hardware
IWC fits Santoni straps to these. Replicas usually ship with something stiffer and shinier. Look at the stitching density, the taper, and the engraving depth on the buckle. Spring bars should be solid and the lug holes should line up without forcing.
Pre-purchase checklist
- Confirm which movement the reference year should have, then confirm what is inside.
- Ask for a side profile photo with calipers in frame.
- Ask for a macro shot of the dial at an angle, not straight on.
- Ask for a video of the chronograph starting, stopping, and resetting.
- Check the date flips cleanly and centers in the window.
- Confirm the caseback type matches the era.
- Ask what happens if it arrives running fast or losing time.
What to expect day to day
Treat water resistance as decorative. A 30m rating on the original is already modest, and replica gaskets are not something I would trust in a shower. Have a watchmaker look at it before relying on it, and expect a service at some point if you actually run the chronograph. The honest framing is this: a good fake IW371432 is a well-finished object that photographs beautifully and keeps decent time. It is not the original, and the gap shows up in the details you only notice after a month on the wrist.