The best replica IW371446 for most buyers is the 40.9 mm stainless steel Portugieser Chronograph on a leather strap, built on a modified Valjoux 7750 with the correct sub-dial layout at 12 and 6. Three things decide whether an example is worth owning: case thickness that stays near the genuine 12.3 mm, dial details that match the original (leaf hands, applied numerals, a fine railway minute track), and a movement that keeps running seconds at 6 o'clock without turning into a repair bill. The sections below take each criterion in turn and then match specific versions to specific buyers.

Best overall: steel case, leather strap, A7750 inside

This is the configuration most replica IW371446 listings aim for, and it is the one to buy if you want a single watch that covers office wear and weekends. The case is slim enough to sit under a cuff, the dial reads clean from across a table, and the strap is easy to swap when the leather wears out.

Pros

  • Proportions match the reference people actually search for: 40.9 mm wide, short lugs, a thin polished bezel.
  • The 7750 architecture forces the sub-dials to 12 and 6, so the layout cannot drift the way quartz copies do.
  • Leather strap and simple buckle are cheap to replace and hard to get wrong.
  • Reads as a dress chronograph rather than a sports watch, which suits more outfits.

Cons

  • Polished bezel and case flanks pick up scratches fast.
  • The genuine watch is rated to 30 m, so treat any replica as splash-proof at best.
  • A7750-based cases run thicker than the spec sheet suggests once the rotor and caseback are counted.

Best for: a first replica chronograph, or anyone who wants one watch that works with a suit and with jeans.

Criterion one: case profile and thickness

Slim is the hardest thing to copy. The genuine Portugieser Chronograph measures 12.3 mm thick, and a replica that lands at 14 mm or more looks bloated on the wrist even when every other detail is right. Ask for caliper photos across the caseback, not wrist shots. Then look at the lugs: on a good case they curve down toward the strap and the crown sits flush with the flank instead of standing proud.

Pros of buying on this criterion

  • A correct case height fixes the single most visible flaw, the silhouette in profile.
  • Thin cases tend to come from the better tooling, so dial and hand finishing usually follows.
  • Lug geometry that matches the original means standard 20 mm straps fit without gaps.

Cons

  • Slimmer cases often use a thinner caseback gasket, which trades water resistance for profile.
  • You will pay a premium for a measured 12 to 12.5 mm, and the difference is invisible from a metre away.

Best for: buyers who wear the watch with short sleeves and know the profile will be seen from the side.

Criterion two: dial, hands and sub-dial spacing

The dial is where replicas win or lose. On the IW371446 family the running seconds sit at 6 and the chronograph minutes counter sits at 12, with slender leaf hands and applied Arabic numerals. Check four things: the gap between the sub-dial edge and the centre pinion, the weight of the printing under the 12, the polish on the leaf hands (they should catch light along a central ridge), and the minute track, which should be fine and consistent rather than thick and smudged.

Pros

  • Applied numerals and a proper minute track make the watch read as expensive at conversation distance.
  • Correct sub-dial spacing is a structural check, not a cosmetic one, so it exposes weak builds immediately.

Cons

  • Macro photography flatters dials; ask for a phone video in daylight before judging print quality.
  • Some examples use flat stamped hands that lose the faceted look of the original.

Best for: collectors who display watches and will notice hand shape and print weight every time they look down.

Criterion three: movement and the seconds-at-6 question

The genuine calibre 79350 is a 7750 derivative, so the replica world has a genuine head start here. The catch is the seconds-at-6 layout, which routes extra gears through the train. Those gears are the first part to fail on a budget build, and a watchmaker who will not touch a Chinese 7750 is a real obstacle. Ask the seller for a video of the chronograph starting, stopping and resetting to zero, and confirm that the sub-dial at 6 is running seconds rather than a decorative disc.

Pros

  • 7750-based movements are serviceable and parts are widely available.
  • Sweeping chronograph seconds and a snapping reset feel correct in the hand.

Cons

  • The transfer gears add friction and shorten service intervals.
  • Decoration on the display back rarely matches the perlage and engraving of the original.

Best for: buyers who plan to wear the chronograph function rather than leave it parked at zero.

Criterion four: crystal, caseback and strap hardware

Sapphire with an anti-reflective coating on both faces changes how the dial reads in daylight, and it is one of the cheapest upgrades a maker can skip. On the back, look at the engraving depth and the rotor finish. On the strap, check stitch density and whether the buckle tang is polished or brushed to match the case.

  • Good signs: double AR coating, crisp caseback text, a buckle that matches case finishing, a strap with even stitching.
  • Weak signs: glare across the dial at an angle, shallow laser etching on the back, a chrome-plated buckle that feels light.

Best for: anyone who keeps the watch on a desk and looks at it from above more than from across the room.

Which version fits your use case

Daily wear

Choose the leather-strap steel version and budget for a spare strap. Avoid anything with heavy plating, since wrist wear shows on plated edges first.

Collection gap

Pay for the correct case thickness and dial print. This is the version you will handle and compare, so the movement matters less than the geometry.

First replica

Stay with the standard configuration and a seller who accepts returns. A well-built base model teaches you what to look for before you spend on a rarer dial variant.

Buying checklist

  1. Request caliper photos of diameter and thickness, side-on and across the caseback.
  2. Ask for daylight macro shots of the dial and a video of the chronograph running.
  3. Confirm the sub-dial at 6 is running seconds, not a fixed disc.
  4. Ask which movement is fitted and whether the seller will service it.
  5. Check the return window and whether returns cover movement faults.
  6. Confirm strap size and buckle type before paying.

Factory labels such as ZF, APS or V6F appear in most listings. Treat those names as seller shorthand rather than proof of origin, and judge the watch on the measurements and video you requested.

Verdict

Buy on the case profile first, the dial second, and the movement third. A replica IW371446 with correct 12.3 mm proportions and clean dial printing will convince at arm's length even if the rotor engraving is imperfect, while a thick case with flat hands never will. If you want one recommendation, take the slim steel case on leather from a seller who will send measurements before you commit.