Top pick for a quick verdict on a suspect IW323707: inspect the movement and the caseback engraving as one check, because those two areas carry the most machine work a counterfeiter has to reproduce. The criteria used here are the ones that hold up in real buying situations: what a check can prove without opening the watch, how easily a replica can hide from it, and whether it still works when all you have is a listing photo and a phone screen.

The reference number is the first thing to decode. IWC writes references as a stem plus a variant, so IW323707 reads as IW3237 with variant 07, and that suffix normally fixes the dial color, strap choice or market inside one case family. If a seller describes the same number as a different case size, a different metal, or a complication the stem does not support, the conversation is over before you look at a single photo.

Top pick: movement and caseback together

Ask for a photo with the back off, then look at the rotor, the bridges and the engraving inside the caseback. Genuine IWC automatics of this generation show even striping or perlage, cleanly cut caliber numbers, and branding engraved into the rotor with sharp edges. Replicas usually run a stock automatic, sometimes with a decorated plate screwed on top, and the tells are soft lettering on the rotor, a caliber stamp that does not match the reference, or a movement ring that sits loose in the case.

Pros

• Catches most low tier and mid tier fakes in one look
• The caliber number can be checked against the reference itself
• Hand finishing is expensive to copy and shows under a loupe

Cons

• Requires the seller to open the watch or to send photos with the back off
• A top tier replica can use a Swiss clone movement with a copied rotor
• Some sellers refuse to open a watch they claim is factory sealed

Best for: an in person meeting or a seller who will send movement photos on request. No movement photos at all is itself an answer.

Caseback engraving, read from the outside

Flip the watch over and study the stamping: reference number, case material, water resistance rating and serial. Genuine engraving is even in depth, sits square to the case, and matches the paperwork. Replicas often show shallow laser etching, digits that are spaced wrong, or a serial that repeats across several listings from the same seller. A stock caseback that does not match the dial variant is another common slip.

Pros

• No tools needed and no risk of damaging the watch
• Serial and reference can be compared against photos of the same piece
• Depth and crispness are hard to fake at this scale

Cons

• A polished or refinished case can soften genuine engraving and look wrong
• Some sellers photograph the caseback at an angle that hides the text
• Good replica casebacks exist and pass at arm's length

Best for: remote buys where you only get photos and want a fast filter before asking for more.

Dial, hands, date and crystal

Check the printing first. Text should sit on the dial evenly, with no thick edges or ink spread, and applied markers should line up with the minute track. Look at the date window position, the font on the date wheel and the alignment of the number inside the window. Lume that glows a different color from the hands, or that is applied unevenly around a marker, points to a replica. On the hands, the polished and brushed sides should meet in a crisp line.

Pros

• Visible in any decent product photo or in hand under daylight
• Multiple small errors add up fast once you know what to look at
• No disassembly, no tools, no risk

Cons

• Blurry or overexposed photos hide most of these details
• Dial swaps are common on genuine watches, so a mismatch is not proof by itself
• Top tier replicas copy print and markers closely

Best for: a first pass on a listing where the seller has posted large, sharp images.

Crown, bracelet and clasp

Wind and set the watch if you can. A screw down crown should thread smoothly and seat flush, with the logo engraved cleanly on the head. On the bracelet, look at end link fit, the gap between links, and whether the surfaces alternate between brushed and polished the way the reference should. Clasp stamps are frequently wrong on replicas: wrong font, wrong depth, or a logo placed off center. Screws that strip or sit proud of the link are another sign.

Pros

• Touch and feel expose problems that photos hide
• Crown action is hard to fake and easy to test in seconds
• Clasp and bracelet codes can be compared with known genuine examples

Cons

• Needs the watch in hand
• A genuine bracelet may have been replaced or stretched with age
• Aftermarket straps hide the original hardware

Best for: the final five minutes before you hand over money in person.

Cheap fake or 1:1 replica: which one are you looking at

The word fake covers a wide range of products. At the bottom you get quartz movements, printed dials and hollow bracelets. In the middle you get a decorated clone automatic, a decent case and correct proportions. At the top, often sold as 1:1 or super clone, the case profile, dial furniture and clasp markings are copied closely and the movement is a Swiss or Japanese base. Genuine examples of IWC references from this era trade for thousands on the secondary market, while replicas sell for a small fraction, so an unusually low price on a watch sold as original is a warning, not a bargain.

• Low tier: fine as a costume piece, fails every check above
• Mid tier: wears well, survives a casual glance, shows flaws under a loupe
• Top tier: closest match in photos, still not a genuine watch and should never be sold as one

If the plan is to pass it off as genuine, no tier works and the resale becomes fraud. Buy the replica you are happy to describe as a replica.

What to ask before money moves

1. Movement photos with the caseback off, plus the caliber number.
2. Clear photos of the caseback engraving and the serial.
3. A short video of the seconds hand running and the rotor spinning.
4. Whether box, papers and service records come with the watch.
5. Whether the case has been polished or the dial replaced.
6. The return window and the payment method, in writing.

Then check the reference against the maker's own catalog so you know what the variant should look like before you judge the photos.

Verdict

Start with the movement and caseback as a pair, because that check answers the most questions in the least time. Move to dial printing, then to crown and bracelet if you still have doubts. For a remote purchase, caseback and dial photos are usually enough to walk away; for an in person deal, wind the watch and inspect the clasp. Buyers who want a replica should buy one that is honestly described, and buyers who want the real reference should expect genuine market pricing.