The short answer
A fake De Ville Trésor 40mm is a replica of Omega's dress watch line, a slim hand-wound piece with a clean dial, a 40mm steel or gold-tone case, and a sapphire display back on most versions. It is one of the easier dress watches to copy well because the design is simple: thin bezel, applied markers, small or central seconds, leather strap. The hard parts to get right are the case thickness, the dial printing, and the movement you see through the back. If you care about any of those three, the 40mm Trésor is a watch you should inspect closely rather than buy on a photo.
Why the 40mm size matters
Forty millimeters sounds modest until you put it on a dress watch. Without a rotating bezel or thick lugs, the dial reads larger than the number suggests. On a 6.5 inch wrist the lugs usually sit close to the edges, and on a 7.5 inch wrist it looks like what it is, a formal watch that happens to be a comfortable size.
Thickness is the bigger issue. The genuine watch is roughly 10mm thick, which is thin for an automatic and normal for a hand-wound. Many replicas come in closer to 12mm because the case is built around a different movement. That extra 1.5mm to 2mm is the single most common giveaway when the watch is on a wrist rather than in a photo.
Wrist fit checks
- Measure case thickness yourself with calipers if you can. Under 11mm is a good sign.
- Check that the lugs curve down rather than sticking straight out.
- Look at the gap between the caseback and your wrist. A fat case leaves a visible shadow.
The movement is the real tell
The original is hand-wound with a Co-Axial escapement and a power reserve in the 60 hour range. Later versions carry Master Chronometer certification and an anti-magnetic rating to 15,000 gauss. A replica will almost never match that, and it does not need to. What it needs to do is look right through the sapphire back.
Look for finishing on the bridges, a signed rotor if it is automatic (a clear mismatch on a hand-wound design), and whether the movement fills the case. A small movement rattling around inside a 40mm case is obvious once you open it. A well-chosen hand-wound clone sits flush and looks plausible.
Dial, case, and finishing details
Dress watches live or die on printing. On the Trésor the markers are applied, not painted, and they catch light along one polished edge. Replica dials often use flat markers with a printed outline instead. The text should be crisp at arm's length, with even spacing and no blur at the edges of the letters.
- Mineral or sapphire crystal: sapphire is standard on the real one, and it changes how the dial reflects light.
- Sub-dial or central seconds: depends on the reference. Match the layout to the version you are copying.
- Case finishing: polished surfaces should be mirror-clean, with a defined line where a brushed section starts.
- Caseback engraving: depth and font weight vary a lot between factories.
What to verify before you buy
- Ask for a photo of the watch on a wrist, not on a table. Proportions only make sense in context.
- Get the measured thickness, not the listed one.
- Confirm the crystal material.
- Ask which movement is inside and whether it is hand-wound or automatic.
- Check the strap width at the lugs. Twenty millimeters is typical, and a mismatch looks wrong immediately.
Strap and daily wear
These watches ship on leather, and the strap is usually the weakest part. A thin alligator-grain strap that matches the case tone will do more for the watch than any other single upgrade. The Trésor is not a sports watch, so treat it that way. No swimming, no showering, and no leaving it in a hot car. Hand-wound movements also want to be wound at roughly the same time each day, and you should feel resistance rather than grit.
Bottom line
The fake De Ville Trésor 40mm works best for someone who wants a thin, quiet dress watch and understands that the case profile is where the money goes. Nail the thickness, the dial printing, and the movement layout, and it reads convincingly on the wrist. Miss any of those and no amount of polishing will hide it.