The top pick for most buyers is the steel case with the silver-plated dial, applied numerals and a black leather strap, because that combination exposes the flaws that give a first copy away: uneven sub-dial spacing, soft printing and mismatched hand finish. Every option below is judged against four criteria: dial layout accuracy (twin sub-dials at twelve and six, correct spacing and diameter), case proportions (roughly 41 mm wide, thin bezel, short curved lugs), hand and marker finish under a loupe, and how the chronograph behaves when you press the pushers.

What the replica IW376045 has to get right

The IW376045 sits in IWC's Portugieser chronograph family, and that family is defined by a wide open dial: a thin bezel, tall applied Arabic numerals, leaf-shaped hands and two sub-dials stacked vertically. None of that is hard to copy badly. A cheap version will shrink the sub-dials, drift them off centre, or print the minute track too thick. A good version reproduces the proportion of empty dial space, which is the whole point of the design.

• Dial balance: the sub-dials should sit on the vertical centre line, sized close to each other, with the lower one carrying running seconds.
• Print quality: the railroad minute track and the brand text should be crisp at arm's length, not just in a zoomed photo.
• Hand finish: leaf hands need a clean bevel and a polished top surface that catches light along the full length.
• Case profile: a thin bezel and a case that reads slim on the wrist, not a slab with a domed back.

Steel case, silver dial, black strap: the top pick

Silver dials are unforgiving. Any smudge in the printing, any gap between an applied numeral and the dial surface, any mismatch between the hand colour and the marker colour shows up in daylight. That is exactly why this is the version to buy: if the seller's photos hold up on a silver dial, the rest of the watch usually holds up too.

Pros

• Highest contrast between hands and dial, so legibility problems become obvious immediately.
• Works with almost any strap, from black leather to brown suede, so you can swap without hunting for a match.
• Easiest variant to compare against reference photos of the genuine watch side by side.

Cons

• Shows dust, fingerprints and light scratches on the case flanks more than a dark dial does.
• Printing flaws are harder to hide, so a weak example is a weak example with nowhere to go.

Who it suits: first-time buyers and anyone who wants one watch that covers office wear and weekend wear without a second thought.

Blue-dial version

Blue dials photograph well, which cuts both ways. A deep sunburst finish hides minor printing softness, but it also hides a dial that is flat and lifeless in person. Ask for an unedited photo in indirect daylight before you commit.

Pros

• More forgiving of small imperfections in printing and marker seating.
• Reads dressier with a steel bracelet and more casual on leather, so it is flexible.
• Less common in the wild, which matters if you dislike seeing the same watch on every wrist.

Cons

• Colour accuracy is the risk: many copies are too purple or too bright compared with the original.
• Harder to judge from seller photos, so you rely more on the seller's reputation.

Who it suits: buyers who already own a silver-dial watch and want a second option with more colour.

Automatic versus quartz movement

The movement decides how the chronograph feels, not just how the watch runs. A mechanical chronograph has a firm pusher action with a defined click at start, stop and reset. A quartz chronograph often feels lighter and the sweep of the running seconds is a tick rather than a glide, which is the first thing a knowledgeable friend will notice.

Pros of automatic

• Correct sweep of the running seconds hand and a pusher feel closer to the real thing.
• Usually paired with better case finishing, since the same tier of build tends to go together.

Cons of automatic

• Heavier, thicker and more expensive to service if something goes wrong.
• Needs winding if you do not wear it daily.

Pros of quartz

• Accurate, low maintenance and cheaper, which leaves budget for a better strap.
• Thinner case in some builds, which suits a slim wrist.

Cons of quartz

• Ticking seconds hand is an instant tell.
• Pusher action often feels vague, especially on the reset.

Who it suits: automatic for anyone who cares about how the watch behaves; quartz for a gift, a beater or a buyer who wants the look with zero upkeep.

Case thickness and lug shape

A Portugieser-style case lives or dies on its profile. Ask for a side-on photo. The bezel should be thin, the mid-case should taper, and the lugs should curve down rather than stick out straight. If the lugs are straight and thick, the watch will sit proud on a small wrist and look like a dinner plate.

• Check: lug-to-lug distance, not just case diameter. Under about 50 mm total is comfortable for most wrists.
• Check: whether the caseback is flat or domed, since a domed back adds height you feel but cannot see.

Strap, clasp and hardware

Straps are where budget copies cut hardest. A stiff, glossy strap with plastic-looking edge paint will undermine an otherwise decent watch. Look for a matte finish, clean stitching and a buckle with a proper tang and a crisp engraving rather than a stamped blob.

• Ask whether the strap is genuine leather or a synthetic with a leather grain print.
• Confirm the lug width so you can budget for a replacement strap from day one.

Seller checklist before you pay

1. Request photos of the actual watch, not catalogue renders, including a close-up of the dial printing.
2. Ask for a short video with the chronograph running, started and reset, so you can hear and see the pusher action.
3. Confirm the exact dial colour and strap option in writing, since variants are often swapped by mistake.
4. Check the return window and whether the watch ships with the strap shown in the photos.
5. Ask what happens if the watch arrives with a misaligned sub-dial hand, which is the most common defect.

One last point on expectations: a first copy is a look-alike, not a restoration project. Buy the version whose flaws you can live with, from a seller who answers questions with new photos rather than stock text.