The best replica Omega 3604 is not the one with the longest sales page. It is the one that matches the proportions of the source watch: a 34 to 36 mm case, a domed acrylic crystal, a screw-down case back, and a clean printed dial with no date window unless the original had one. Those four checks, plus a movement that a watchmaker can still service, decide most of the outcome. The rest of this guide explains how to apply them when a listing uses the number 3604 as loose shorthand.
What 3604 Signals in a Listing
Vintage Omega reference numbers from the 1950s and 1960s are case references, and sellers use them in inconsistent ways. Some listings mean the case code, some mean a caliber family, and some borrowed the number from an auction result. Before you compare copies, pin down the source watch: diameter, lug width, dial layout, and hand style. Omega's own vintage reference and caliber database is the fastest way to confirm what a number belongs to, and auction archives show which dial variants shipped with it. If a seller cannot name the watch the number maps to, there is nothing to compare the replica against.
Case and Crystal: Where Copies Split Into Two Camps
Vintage-accurate case, 34 to 36 mm
- Pros: sits on the wrist like the original, correct lug shape and thickness, acrylic dome bends light across the dial the way buyers expect, works on small wrists.
- Cons: harder to find, fewer makers build it, some buyers read the smaller size as underwhelming next to modern sports watches.
Modernized case, 38 to 40 mm
- Pros: more presence on the wrist, easier to source, easier to fit modern straps, sapphire options are common.
- Cons: lugs overhang a small wrist, the case is too thick, sapphire removes the vintage look, and the proportions give the copy away to anyone who knows the original.
Use case: if you want the watch to read as vintage, take the accurate case. If you want a daily beater and do not care about matching a 1960s silhouette, the modernized case is the practical choice.
Movement: Beat Rate Matters More Than Branding
High-beat clone, 28,800 vph
- Pros: reliable, cheap to replace, parts are everywhere, easy for any watchmaker to regulate.
- Cons: the seconds hand sweeps too smoothly for a watch of this era. Most vintage Omega automatics of the 500-series run at 19,800 vph, so the smoother sweep is a visible tell.
Low-beat vintage-style movement
- Pros: correct sweep rate, closer to the original feel, better match for a vintage build.
- Cons: less common, fewer service options, some examples keep poor time.
Use case: buy the high-beat clone for a wearer, the low-beat for a display piece or a gift to someone who looks at the seconds hand first.
Dial, Hands, and Printing
Check the weight of the brand text, the spacing between the logo and the model line, and whether the logo is applied or printed. Dial print on a good copy stays crisp under a loupe at 10x. Hands should be dauphine or leaf shaped with a polished bevel, not stamped flat. Lume plots should sit inside the minute track, not floating over it.
- Pros of faux aged lume: hides color mismatches, suits a vintage build.
- Cons of faux aged lume: every plot ages the same way, which no real watch does, and it reads as costume on a clean dial.
Case Back, Crown, and Strap
Engravings should be stamped, not laser etched, and the case back shape should follow the original curve. Crown diameter is a common failure point: an oversized crown ruins the profile. Beads-of-rice bracelets and simple leather straps both work, but hollow end links that rattle are a sign of a cheap build.
Seller Checks Before You Pay
- Ask for photos of the actual watch, not catalog images.
- Ask for caliper measurements of case diameter and thickness.
- Ask for a movement photo and the beat rate.
- Confirm the return window and whether the seller services what it sells.
Recommendation by Use Case
For a first vintage-style replica, choose a 35 mm case with an acrylic crystal and a high-beat clone movement. For a collection piece meant to sit next to genuine vintage watches, hold out for the accurate case and a low-beat movement. For a daily wearer, size and serviceability beat every other detail. Skip any listing that will not answer basic questions about the watch it is copying.