The short answer
There is no single "Seamaster 300 007." Two different Omegas wear that name in searches. The 2015 Seamaster 300 "Spectre" was a 41mm steel watch capped at 7,007 pieces. The 2020 Seamaster Diver 300M 007 Edition, built for No Time to Die, is a 42mm Grade 2 titanium watch with a brown dial and a titanium mesh bracelet. Replica makers copy both, and the copies miss on different points. Match the replica to the exact reference you mean, because specs from the two watches do not swap.
Which 007 Seamaster people mean
Seamaster 300 Spectre (2015)
Stainless steel, 41mm, 300m water resistance, black ceramic bezel with a Liquidmetal dive scale, lollipop seconds hand, black and grey NATO strap, calibre 8400 Master Co-Axial. It was a limited run, and that fact is stamped into the watch rather than printed on a card.
Seamaster Diver 300M 007 Edition (2020)
Grade 2 titanium, 42mm, 300m, brown aluminium bezel insert, no date, warm brown "tropical" dial, titanium Milanese mesh bracelet, calibre 8806 Master Chronometer with 55 hours of reserve. This one was not numbered, so a seller who quotes you a serial-as-edition-number is improvising.
Where replicas give themselves away
- Weight. Titanium is the whole point of the 2020 model. A steel copy of a titanium watch feels wrong in the hand, and that is hard to photograph around.
- Bezel insert. Aluminium has a matte, faintly grainy surface. Printed fakes look glossy or too even under a lamp.
- Mesh and clasp. Real titanium mesh drapes and folds without stiffness. Check the clasp engraving depth and the fit of the links at the fold.
- Dial and lume. The 007 Edition dial is a muted brown, not chocolate and not bronze. Vintage-toned lume should read cream in daylight. Chalk white is a tell.
- Movement. Master Chronometer watches ship with a METAS certification card tied to the movement. No card, or a card that does not match, ends the conversation. Rotor finishing under a loupe is the second check.
The legal part most guides skip
Replica watches are counterfeits. In the United States, trafficking in counterfeit goods is a federal crime, and customs officers can seize counterfeit imports at the border. Buying one for yourself sits at the low end of the risk scale. Reselling, importing several, or shipping one across a border moves it much higher. There is also a practical cost: Omega will not service a counterfeit, and most watchmakers with a parts account will not touch one. The 8400 and 8806 families use parts that are not sold on the open market, so a broken fake tends to stay broken.
What a fair comparison looks like
Compare like for like: same reference, same case material, same bracelet configuration. Ask for photos of the caseback engraving, the clasp, the crown threads, and the movement with the back off. Weigh the watch if you can. Check that the lume color matches the reference and not the marketing render. Then decide whether the gap between the copy and the real thing is one you can live with, because the gap is always there somewhere, and it is usually in the details you touch every day.