A fake Omega De Ville 424.13.40 gives itself away in four places: case size, dial printing, crown, and caseback. The genuine De Ville Prestige 39.5 mm measures 39.5 mm across, about 10 mm thick, with 20 mm lugs, and it carries the Co-Axial calibre 2500. Copies that run past 40.5 mm or use a 21,600 vph movement do not survive a close look.

What the 424.13.40 Reference Covers

The 424.13.40 group is the Omega De Ville Prestige in its 39.5 mm form, sold on leather straps with a solid caseback. Steel and gold-cap versions sit in the same family. The dial runs center seconds with a date at 3 o'clock, leaf-shaped hands, and a domed sapphire crystal with an inner anti-reflective coating. Water resistance is rated at 3 bar, and the caseback carries the Seahorse medallion with the reference stamped around the rim.

What You Need

  • Digital calipers
  • 10x loupe
  • Soft cloth and lint-free gloves
  • Reference photos of the exact sub-reference you are checking
  • Small scale, optional

How to Check a Fake De Ville 424.13.40

  1. Measure the case across the 3 to 9 o'clock line. Genuine spec is 39.5 mm, so treat anything from 39.2 mm to 39.8 mm as normal.
  2. Measure the case thickness from the caseback center to the crystal top. The real watch sits near 10 mm, and most low-grade copies land at 12 mm or more.
  3. Measure the lug width at the spring bar. It should read 20 mm with a straight inner edge.
  4. Inspect the crown at 3 o'clock. It pulls straight out, sits flush with the case band, and carries a stamped Omega symbol.
  5. Study the dial under the loupe. The applied OMEGA logo has clean edges, and the De Ville and Co-Axial Chronometer text prints sharp with no fill or bleed.
  6. Check the date window. The aperture has a crisp frame, a centered numeral, and the correct font weight at 3 o'clock.
  7. Look at the hands. Leaf-shaped hands have polished facets and reach into the minute track without overshooting.
  8. Turn the watch over. The Seahorse medallion shows deep relief, and the 424.13.40 reference stamps into the rim with even spacing.
  9. Watch the seconds hand for 30 seconds. The calibre 2500 beats at 25,200 vph, which reads as seven small steps per second. A six-step tick points to a cheaper 21,600 vph movement.
  10. Check the strap and buckle. The leather has a fine grain and the pin buckle is signed on the back.

Red Flags on Low-Grade Copies

  • Case wider than 40 mm or noticeably thicker than the genuine profile
  • Printed logo instead of an applied metal OMEGA emblem
  • Date window with a raised plastic ring or an off-center numeral
  • Caseback laser-etched flat instead of struck in relief
  • Mineral glass with a purple glare instead of domed sapphire
  • Crown that unscrews or sits proud of the case band

Where Good Replicas Still Fall Short

A high-grade copy can match the 39.5 mm case, the 20 mm lugs, and the dial layout well enough to pass at arm's length. The movement is the hard part. An authentic Co-Axial calibre 2500 has 27 jewels, a 48-hour power reserve, and chronometer certification, and no clone movement reproduces the coaxial escapement geometry. Open the caseback only if you own the watch, and compare the rotor engraving and balance frequency to reference photos before you trust a seller.

Before You Buy

Match the full reference number, not just the 424.13.40 stem. Sub-references within the family differ by dial color, case metal, and strap, and a seller who cannot name the exact string is a seller worth skipping. Ask for caliper photos next to a ruler, a shot of the crown, and a straight-on dial photo in daylight. Those three images answer most authenticity questions before money changes hands.