The most useful check on a fake Jaeger-LeCoultre 387874 is the caseback: match the reference engraving, the font, and the spacing against the numbers Jaeger-LeCoultre publishes for that exact reference before you look at anything else, because that one step removes most weak listings. From there, judge four criteria in order: movement finish and engraving, dial and hand finishing, case profile and lug geometry, and the proof the seller can actually show you. A box, a card, and a foil sleeve come last, since they are the cheapest part of a listing to fake and the least useful signal about the watch itself.

Reference number and caseback engraving

Reference 387874 maps to one specific case, dial layout, and metal combination, and copies often borrow parts from nearby references in the same family. Confirm the factory spec first, then compare.

Pros

  • Crisp engraving with consistent depth across the whole line of text
  • Reference number that matches the dial layout on the same watch
  • Serial placed where the original places it, not squeezed into a gap
  • Metal marking and hallmarks that fit the market the original was sold in

Cons

  • Reference number that does not correspond to the dial in front of you
  • Shallow, dotted engraving that looks printed rather than cut
  • The same serial appearing on several listings, which signals bulk production
  • Reference and serial in the wrong order or the wrong line spacing

Use case: if you will wear the watch and never open it, this is the check you live with, so weight it high.

Movement finish and engraving

Movement quality separates a copy that runs for years from one that goes back in a drawer. Judge architecture first, decoration second.

Pros

  • Rotor shape and bridge layout that follow the original design, not a generic outline
  • Even striping or cotes with no smeared polishing at the edges
  • Engraved brand text on rotor and bridges with a steady font and depth
  • Blued or polished screws rather than painted heads

Cons

  • Decorative plates laid over a basic movement to fake depth
  • Printed text where the original engraves it
  • Screw and jewel positions that do not line up with the original layout
  • Loose rotor and loud winding feel

Use case: weight this highest when the watch has an exhibition caseback. With a solid back, movement quality matters for reliability rather than appearance.

Dial, hands, and crystal

The dial is what people read from across a table, so treat it as a display criterion, not a detail.

Pros

  • Applied markers that sit flush and catch light at the same angles as the original
  • Printed text with sharp edges and the correct font weight
  • Date window framed and centered, with the right numeral font
  • Hands of the correct length that reach their markers

Cons

  • Printed markers standing in for applied ones
  • Text that is too heavy, too thin, or spaced wide
  • Date wheel with an off font or an off-center window
  • Crystal coating that throws a different reflection than the original

Use case: for a watch worn in public, put this criterion ahead of movement finish.

Case profile, lugs, and strap

Dimensions and geometry decide whether the watch feels right, and they are easy to compare against published specs.

Pros

  • Case thickness close to the documented figure for the reference
  • Lug curve that matches the strap and sits on the wrist without a gap
  • Crown sized and detailed to match, with a clean logo
  • A sharp line kept between brushed and polished surfaces

Cons

  • A case that is thicker than the reference spec
  • Lug tips rounded off from heavy polishing
  • A crown that sits too far out or rocks when you set the time
  • Strap with the wrong taper, stitch pattern, or hardware finish

Use case: choose this first if you care about how the watch feels on the wrist rather than how it photographs.

Seller proof and return terms

Terms carry more weight than marketing photos, because a return window is the only remedy you have after delivery.

Pros

  • Photos of the exact unit, including the caseback and crown
  • A plain statement of what is included in the sale
  • A written return window with clear conditions
  • A straight answer when you ask about the movement inside

Cons

  • Stock images reused across several listings
  • No photo of the caseback, or a refusal to take one
  • No stated return terms
  • Payment requested outside a method you can document

Use case: a clean set of terms beats a better-looking photo set on every purchase.

How to decide

  1. Confirm the factory reference spec for 387874 from the brand's own reference page.
  2. Ask for caseback photos of the specific unit and compare engraving depth and spacing.
  3. Decide whether the back is open or closed, then weight movement or dial accordingly.
  4. Check case thickness and lug shape against the published figures.
  5. Confirm the return window in writing before you pay.

For a first copy of reference 387874, the safest route is a seller who photographs the actual unit, states a return window, and answers a direct question about the movement. If the caseback is open, pay for movement finish and accept a plainer strap. If the caseback is closed, spend that budget on the dial and case geometry instead. Skip any listing that will not show you the back of the watch.