Short answer: A fake IW376067 gives itself away in four places: the engraving on the case back, the spacing of the dial text, the feel of the internal bezel crown, and the finish on the movement. Work through those four checks before you spend time on anything else.
Why This Reference Gets Copied
The IW376067 sits in the IWC Aquatimer chronograph line: a 44 mm steel dive watch with an internal rotating bezel, a day and date window at 3 o'clock, and a chronograph running on the calibre 79320. Demand for that mix is steady, the case shape is simple to machine, and the base movement is a common Valjoux 7750 architecture. Those three facts make it a target for replica makers. They also mean a careful buyer can catch most fakes with a loupe and a phone.
What You Need Before You Start
- A 10x jeweler's loupe
- A phone with the IWC reference page open
- Bright, angled light rather than overhead light
- Calipers, if you have them
- A watchmaker contact for an independent inspection
Inspection Sequence
- Look up reference IW376067 on the IWC site and note the case diameter, dial options, and strap codes.
- Measure the case across the widest point and compare the number to the catalog spec.
- Turn the watch over and read the case back engraving through the loupe.
- Compare the font weight of the reference number against a photo of a genuine case back.
- Angle the light across the dial and check the gap between the IWC wordmark and the Schaffhausen line.
- Check the day and date aperture, where both discs should sit level and centered.
- Rotate the internal bezel crown and count the clicks from stop to stop.
- Press the chronograph pushers and start, stop, and reset the sweep hand.
- Ask the seller to have a watchmaker open the back and photograph the movement.
- Compare the rotor engraving and the beat rate against the specs for calibre 79320.
Case Back and Engraving
Replica case backs fail on depth. Genuine IWC engraving is cut into the metal with a crisp edge and even depth across the whole block of text. Fakes are stamped or laser etched, which leaves a shallow mark with soft edges and a raised burr along the letters. Run a fingernail across the reference number. Real engraving catches the nail on both sides of each character. Etching feels flat.
Dial, Hands, and Crystal
Dial printing is the second failure point. Genuine IWC text has even spacing and sits on a clean lacquer surface. On a fake, the wordmark crowds the Schaffhausen line, the lume plots sit at uneven heights, and the date disc font is wrong. Check the anti-reflective coating as well. Genuine AR coating on this line cuts glare from an angle without turning the crystal blue. A purple or blue tint points to a cheap aftermarket crystal.
Movement and Calibre
The IW376067 runs the calibre 79320, an IWC-modified Valjoux 7750 with a day and date display. Ask for a photo of the movement with the rotor turned aside. Look at the finish on the bridges, the engraving on the rotor, and the position of the shock absorber. A stock 7750 with no IWC marking, or a clone with rough edges on the winding rotor, settles the question. A watchmaker with a timegrapher can also read beat rate and amplitude, which separates a serviced movement from a worn one.
Seller and Listing Signals
- No photo of the case back or movement
- A price far below the market range for the reference
- Replica or clone wording buried in the description
- Stock catalog photos instead of images of the actual watch
- A seller who refuses a video call or an independent inspection
Legitimate sellers of pre-owned watches provide dated photos of the case back, the movement, and the warranty card. If a listing shows only front-of-dial images, treat the reference as unverified.
When to Walk Away
Walk away when the case back photos are blurry, when the seller dodges the movement question, or when the price sits outside the range for a used example of the reference. Two clean checks are not enough. Every item on this list has to pass before you send money.