Short answer
A fake IW329025 is a copy of an IWC watch sold under that reference number. IWC does not publish a public spec sheet for every reference in the 3290 block, so confirm the exact model, case size, and caliber with IWC before you use those numbers as a test.
Check the caseback engraving
IWC cuts the reference number, serial number, and model name into the caseback. On a replica the font runs wide or thin, the digits sit off center, and the cut is shallow. Look at the spacing between characters and the depth of the cut. Real engraving holds the same depth across the whole text.
Serial number against the reference
IWC assigns serials in blocks. A serial that falls outside the block used for the 3290 family points to a copied or swapped caseback. IWC service can confirm a serial if you send the number and photos.
Movement
Replicas of IWC pilot watches use a Chinese or Japanese automatic caliber. Rotor decoration, jewel count, and beat rate differ from the real calibers. An IWC rotor carries the brand mark, the caliber number, and Geneva stripes or circular graining.
Many IWC pilot watches have a closed caseback, so you cannot see the movement without opening the case. If you cannot open the watch, use the other checks.
Dial, hands, and print
View the dial print at 10x magnification. Real IWC print has sharp edges and even spacing. Fakes show fuzzy edges, thick strokes, and uneven gaps between the numerals and the minute track. The date window on a replica sits too far from the center or shows a font IWC does not use. Lume on a fake is patchy and dim.
Crystal and coating
IWC applies anti-reflective coating on both sides of the sapphire on many pilot models. That coating gives a blue or purple tint at an angle. A fake often has no inner coating, so the glass reflects more light and the dial looks flat under a lamp.
Case, crown, and bracelet
Measure the case with calipers. Replica cases run 0.3 mm to 1 mm off the stated size. The crown on a fake threads with a rough feel and stops short of the case. Bracelet end links on a replica leave a gap at the lugs. Clasp engraving is stamped, not cut.
Price and paperwork
Real IWC pilot watches in the 3290 block sell in the four-figure range and up on the secondary market. A listing far below that range, with no box, no papers, and no service history, is a warning sign. Cards and booklets on replicas use the wrong fonts, and the warranty card number does not match the case number.
Steps before you buy
- Photograph the caseback and send the serial to IWC service.
- Ask for a movement photo if the watch has a display back.
- Compare measured dimensions with the IWC spec sheet.
- Have a watchmaker open and inspect the watch.
If the seller refuses any of these steps, stop.