Short answer
The number IW545115 does not match a reference in IWC's published catalog. IWC codes in the 5451 block sit in the Portuguese hand-wound family. Sellers who list a "replica IW545115" mean a Portuguese-style dress watch: round case, thin bezel, small seconds at 9 o'clock, printed Arabic numerals. Ask the seller for the factory name, the case diameter, and a photo of the movement before you pay. If the seller sends catalog images instead of photos of the actual watch, stop there.
What the 5451 block covers
IWC built the Portuguese line in 1939 for two Portuguese importers who wanted a large pocket-watch movement in a wristwatch case. Hand-wound Portuguese references carry a case about 44 mm across and about 10 mm thick, in steel or 18k gold. The dial has a rail-track minute ring, Arabic numerals, and a small-seconds sub-dial.
Replicas vary more in the dial than in the case. Check the sub-dial position: on hand-wound Portuguese references it sits at 9 o'clock, and many replica dials place it at 6 or remove it. Check the numeral font and the minute hand, which should reach the minute track.
Movement
Genuine pieces use a hand-wound IWC calibre. Replica cases hold one of three groups: a Seagull ST36 or ST19 hand-wound, a modified Asian automatic, or a decorated copy. An automatic rotor under a hand-wound dial is common in the low tier, and it shows through the caseback. Rhodium plating, blued screws, and engraved bridges are decoration. They do not prove Swiss origin. Swiss law requires 60 percent of production costs to be incurred in Switzerland before a watch can carry the Swiss made mark.
Case and finish
Most replicas use 316L stainless steel. Genuine gold references are 18k red or white gold, with hallmarks on the caseback and between the lugs. Plated replicas show wear at the crown and lug edges within months of daily use. Genuine Portuguese models have sapphire crystal with antireflective coating on both faces. Single-sided coating on a replica gives a blue tint at an angle. Caseback engraving carries the reference number, the case number, and the Swiss made stamp. Font depth and spacing differ between factories.
Price ranges
Listings for Portuguese-style replicas run from about $90 to $1,200. The low end uses an unmarked Asian hand-wound movement and mineral glass or single-coated sapphire. The middle tier, about $250 to $600, adds a decorated movement and a closer dial. Above $800, sellers claim Swiss movements and 1:1 cases. Ask what is inside the case before you accept the top tier. Used genuine IWC Portuguese hand-wound watches trade in the thousands of dollars, so price separates the two markets on its own.
Checks before payment
- Reference: search the exact number on IWC's site. Take the result as final.
- Photos: ask for the caseback and the movement, with the crown pulled out.
- Water resistance: no replica listing carries a third-party test result. Keep the watch away from water.
- Customs: US Customs and Border Protection seizes counterfeit watches. Import is prohibited and the package can be destroyed.
- Resale: there is no resale market for replicas. Treat the money as spent.
Bottom line
IW545115 is a listing label, not a confirmed IWC reference. Judge the watch on the dial layout, the movement type, and the case metal, and pay a price that matches what you can see.