Short answer
A fake IW544824 fails four checks: the flying tourbillon at 12 o'clock, the hand-wound movement and its power reserve, the case metal and hallmarks, and the price. Real IW5448 examples sell in the tens of thousands of dollars. Copies sell from about $300 to $2,000. A rotor, a plated case, or a balance wheel that spins in place with no tourbillon cage rules the watch out.
What IW544824 is
IW544824 sits in the IW5448 family, sold by IWC as the Portugieser Tourbillon Mystère. The line ran through the 2000s. The watch carries a flying tourbillon at 12 o'clock under a dial aperture, small seconds at 6 o'clock, and a hand-wound IWC calibre. Case size is about 44 mm. IWC built the family in platinum and rose gold, in low numbers.
The last three digits of an IWC reference encode case metal, dial, and strap. IWC's public reference list does not print every suffix. The caseback engraving and an IWC archive extract are the record to trust, not a listing photo.
Tourbillon check
Look at 12 o'clock with a loupe. A genuine flying tourbillon has a cage that turns once a minute with the balance inside it. The cage is supported on one side, with no upper bridge. Copies in this price range use two shortcuts: a decorated balance wheel that never turns as a cage, or an open-heart cutout over a standard escapement. Time the cage. One full turn takes 60 seconds. Copy cages turn at another rate or stall at low wind.
Wind the crown and set the watch on a desk with no motion. IWC lists the Tourbillon Mystère with a 7-day power reserve. A fake with an automatic movement and a 40-hour reserve stops inside two days. Test this before you pay.
Case, dial, and markings
- Caseback: reference number, case number, "International Watch Co." and "Schaffhausen" in sharp, deep engraving. Copies show shallow, wide lettering.
- Gold and platinum: check the fineness hallmark and the Swiss assay mark. Plated copies show brass or copper at the lug edges and on the caseback rim.
- Weight: platinum has about 2.7 times the density of steel. A platinum watch that weighs like steel is not platinum.
- Dial: applied gold indices, polished bevels, crisp print. Copy dials show soft edges and ink dots.
- Crown: signed, sized to the case, with clean threads.
Papers, price, and provenance
Ask for the IWC box, the warranty card, and service papers. IWC charges a fee for an Extract from the Archives, which lists the reference, the case number, and the date of sale. A watchmaker with a Swiss parts account can read the movement engraving and compare it to the caseback number. Numbers that do not match are a stop sign.
Price is the fastest filter. A Swiss tourbillon costs more to service than a copy costs to buy. Ask the seller what the last service cost and who did the work. Copies arrive with no service history, no archive extract, and a price under $2,500.
Where to verify
Send photos of the caseback, the dial, and the movement to an IWC service center or an independent watchmaker before you transfer money. Request the archive extract in writing. If the seller refuses either step, walk away.