Short answer

A fake Omega De Ville Trésor 424.10.40.20.02.001 lives or dies on two things: the case profile and the dial printing. Copies that get both right are worth the money. Ones that miss the thickness or print the text too heavy are not, no matter how good the listing photos look. Check measured thickness and the movement through the caseback first, then judge everything else.

What this reference is, and why sellers get it wrong

The 424.10.40.20.02.001 string points to a stainless steel Omega De Ville with a silver-toned dial and a slim case in the 40 mm range. In the replica market that same number gets listed as both Trésor and Prestige, and those are two different watches. Prestige is the dressier everyday De Ville with an automatic co-axial movement. Trésor is the thin one, and Trésor-badged versions use a hand-wound caliber with a long power reserve and no rotor at all.

That matters, because a seller who mixes the names is often mixing the details too. Ask which watch the copy is based on. If the answer stays vague, the watch will be vague as well.

Four checks that do most of the work

1. Case thickness and profile

Dress watches are judged by how they sit. A real De Ville is thin, slides under a cuff, and has lugs that curve down toward the wrist. Many copies run 1 to 2 mm thicker, because the movement inside is deeper than the original caliber. I ask for a caliper photo, or I compare side-profile shots of the copy and the real watch at the same angle. Bezel polish, lug shape, and the chamfer where the case flank meets the bezel should all be crisp.

2. Dial printing and applied indices

This is the fastest tell at arm's length. The Omega wordmark and symbol, the CO-AXIAL line, and SWISS MADE under the 6 should be light and sharp, not thick and gray. Indices on the real dial are applied metal, set flat against the surface with a polished facet that catches light. Printed indices stay flat no matter how the light hits them. If the version you are looking at has a date, the aperture should be cut clean and the disc should sit centered.

3. Hands and crystal

Hands should be slim, bright, and even, with no burrs along the edges. The crystal should have a slight dome and sit close to flush with the bezel. A mineral glass with a heavy blue tint is a downgrade, and it shows up on cheaper builds more than sellers admit.

4. Movement and caseback

Ask for a lit photo of the caseback. If the copy is based on a Trésor, there should be no rotor, since the real one is hand wound. See a spinning weight and you know the movement is a generic automatic dressed up to look like something else. On Prestige-based copies an automatic is correct, but the rotor should carry Omega markings and the right caliber number. Stripes, screws, and jewels should look finished, not stamped.

Strap, clasp, and the details people skip

Leather is where mid-tier builds cut corners. Look at the lining, the stitch spacing, and the taper from the lugs down to the buckle. A deployant clasp should close with a firm click and hold the logo at the right depth. Weight is a poor test on this watch. A steel dress piece is light, so a heavy copy is not a sign of quality.

What to ask before paying

• Which movement is inside, and can you send a video of it running?
• What is the measured case thickness, in millimeters?
• Are the indices applied metal or printed?
• Is the front crystal sapphire, and does the back have a sapphire window?
• Can I see a straight-on dial photo in daylight with no filter?
• What happens if the watch arrives with a scratch or a misaligned date?

Price bands and realistic expectations

Cheap copies sell for under $100. Expect a printed dial, a hollow-feeling case, and a strap that creases within weeks. Mid-tier copies land in the $150 to $300 range and get the proportions close enough that only a jeweler with a loupe would catch them across a table. High-tier copies of this exact reference are less common than Seamaster or Speedmaster replicas, so selection is thin and waits happen. What you are paying for is the case and the dial. The movement is a bonus, not the point.