The short answer

Before you spend money on anything listed as a fake Omega 3604, force the seller to say what the number 3604 refers to and to show the movement. That one request separates a watch you can evaluate from a listing built on a vague code. The number 3604 does not identify a single Omega model on its own. It appears in listings as a case reference, a caliber number, or a seller's own stock tag, and sellers lean on it because it sounds precise. If the seller cannot say which of those it is, and cannot send a clear photo of the caseback and the movement, you do not have enough information to judge what you are buying. Buyers who skip this step end up with watches that no watchmaker will service, no collector will buy, and no courier may legally deliver.

What 3604 means in a listing

Omega has used four digit numbers in several parts of its catalog for decades, which is exactly why a bare number is weak evidence. Vintage Omega case references normally appear as two groups of digits separated by a period. Caliber numbers are stamped or engraved on the movement itself. Bracelet and end link codes can also be four digit numbers. A listing that says 3604 and nothing else tells you almost nothing about the watch in the photo, and a seller who cannot explain the number is either guessing or avoiding the question.

What to verify before you pay

  • Movement: ask for the caliber number and a photo with the caseback off. A closed case back in every photo means you are buying a promise, not a watch.
  • Caseback: request a shot of the inner face. On many vintage models the reference is engraved there, and it should agree with the description.
  • Case shape and finish: look for uneven lug drilling, soft edges from over-polishing, and crowns that sit proud of the case.
  • Dial and hands: check the printing under magnification. Blurry text, thick serifs, and mismatched hand lengths are common on counterfeits.
  • Crystal and gaskets: assume nothing about water resistance. A counterfeit case is not tested to any real standard.
  • Provenance: receipts, service papers, and a serial that matches the case are worth more than any seller description.

Bands worth comparing

Treat these as sanity checks rather than specifications. When a listing falls outside them, ask why.

  • Case width: vintage Omega men's watches usually land between about 33 mm and 38 mm across. A claim of 42 mm on a slim vintage dress case needs an explanation.
  • Lug width: vintage leather straps mostly sit at 18 mm or 19 mm, with 20 mm on later pieces.
  • Beat rate: vintage Omega automatics run at rates that change by caliber. Get the caliber number and confirm the rate for that caliber instead of trusting a listing.
  • Case material: solid gold vintage cases carry hallmarks. Absent hallmarks plus a gold claim is a mismatch.

Pitfalls that cost buyers the most

  • Stock photos. If the images match another seller's listing, you are looking at borrowed pictures.
  • Frankens. A case from one watch, a dial from a second, and a movement from a third will never be serviced as one unit.
  • No movement photo. A seller who will not open the case is hiding the one part that decides whether the watch runs.
  • Payment methods with no recourse. Once money leaves by an irreversible route, the watch is yours no matter what arrives.
  • Import and legal risk. Counterfeit watches can be seized at the border, and trafficking in counterfeit goods carries criminal penalties in the United States.
  • No service path. Omega will not service a counterfeit, and cloned movements have inconsistent parts supply.

FAQ

Is a replica Omega 3604 a good buy?

Rarely. You get no warranty, no service network, uncertain parts, no resale market, and legal exposure if the watch crosses a border. The purchase loses most of its value the moment it arrives.

Can a local watchmaker repair one?

Some independent watchmakers will work on generic movements, but many decline, and parts for cloned movements vary from batch to batch. Genuine Omega parts will not fit a counterfeit case.

How do I tell a counterfeit from a genuine vintage Omega?

Match the caseback reference against the caliber, inspect the dial printing under magnification, and look at the finish on the movement. For vintage pieces you can request an Extract from the Archives from Omega, which documents the original reference and delivery date. If the numbers do not line up, walk away.

What should I buy instead?

A genuine vintage Omega with a documented service history, or a current Omega from an authorized dealer. Both hold value and can be repaired by a watchmaker when they need it.