Short answer
You can separate a quality IWC IW545191 replica from a counterfeit by checking four things in this order: case dimensions and finish, dial printing and hand work, the movement and how it winds, and the caseback engraving. A counterfeit copies the silhouette of the watch and stops there. A 1:1 replica carries the same measurements, the same dial layout, and a movement that behaves like the original when you wind and set it.
What you need before you start
- Digital caliper with 0.01 mm resolution
- 10x jeweler's loupe
- Bright angled desk lamp and a lint-free cloth
- Timegrapher, or a watchmaker who owns one
- Photos of the exact unit you will receive, not catalogue images
Inspection steps
- Ask the seller for photos of the actual unit and compare them with official photos of the reference before you pay.
- Place the watch on the cloth under angled light so dust, edge burrs, and polish lines show in the frame.
- Measure the case diameter at 12 to 6 and again at 3 to 9. Repeat each reading twice. A spread above 0.2 mm points to a cast or poorly finished case.
- Measure lug to lug and case thickness, then compare all three numbers with the published specification for that exact reference.
- Read the dial through the loupe: letter height, spacing, and stroke weight on the brand text should match the reference photos. Filled-in counters inside letters signal low-resolution pad printing.
- Trace the minute track. Index marks should sit at an even distance from the chapter ring, with no smudging where two markers meet.
- Inspect the hands edge-on for side burrs, uneven color on blued hands, and lume that sits above or below the rim of the frame.
- Check the small seconds subdial. The hand should sit concentric with the ring, and the ring should be an applied part, not ink on the dial.
- Wind the crown 20 to 30 turns and judge the feel. Grit, a springy stop, or a crown that wobbles on the stem points to a low-grade movement.
- Pull the crown to the setting position and set the time. The hands should move with no backlash and no dragging against the dial.
- Turn the watch over and read the caseback text through the loupe. Reference number, material, and serial should be cut with a sharp edge and even depth. Shallow grey text is laser etching on a counterfeit.
- Run the watch on a timegrapher in four positions. Rate, amplitude, and beat error should stay inside the range the movement maker publishes.
- Ask a watchmaker to pressure-test the case if the seller claims water resistance.
Red flags that end the deal
- Seller sends catalogue photos instead of the unit in hand
- Case diameter off by 0.5 mm or more
- Subdial ring printed rather than applied
- Crown that wobbles or clicks when winding
- Caseback text that rubs off with a thumb
- Brand text with uneven spacing or filled letter counters
After the watch arrives
- Keep the invoice and the seller's photos. They are your record of what was sold and how it was described.
- Store the watch in a dry case away from magnets and direct sun.
- Book a service check every three to five years, or sooner if the rate drifts past one minute a day.
A replica sold as a replica is a product. A counterfeit sold as a genuine watch is fraud, so refuse any paperwork that presents the watch as original. Inspect in the order above and you will know which one you are holding within ten minutes.