The top pick for a replica IW371701 is a 41 mm steel-on-leather automatic build that runs a modified 7750 with a working small-seconds-at-six module, a domed sapphire with anti-reflective coating on the inside, and a black dial with leaf hands and applied numerals. That combination wins because it copies the parts of the watch people actually look at: the dial layout, the crystal curve, and the case profile. The criteria used here are subdial position and spacing, handset shape and finish, case diameter and thickness, crystal curvature and AR tint, movement architecture, and the small details on the caseback and strap.
The reference you are actually shopping for
IW371701 is the steel Portuguese Chronograph with a black dial. It carries leaf-shaped hands, applied numerals, a date window at 3, a small seconds subdial at 6 and a chronograph minutes counter at 12. Inside sits the IWC caliber 79320, a chronograph movement that comes from the Valjoux 7750 family. That single fact drives everything about replica quality, because a standard 7750 places running seconds at 9 o'clock. Moving them to 6 needs an extra transfer gear and a redesigned bridge, and that assembly is the first thing to fail in a poorly built copy.
Top pick: 41 mm automatic with a working seconds-at-six module
This is the build to buy if you want the watch to read correctly on the wrist and in photos. The dial geometry matches the reference, the chronograph pushers feel like a cam-and-lever movement should, and the sweep of the chrono seconds is smooth rather than ticking. Ask the seller to confirm the module was fitted and tested, not just advertised.
Pros
- Correct subdial placement at 12 and 6, so the dial reads like the reference at a glance
- Smooth sweeping chronograph hand and a pusher feel close to the original
- Domed sapphire and polished bezel give the same light play as the genuine watch
- Usually the best finished case of the replica tiers, with crisp lug edges
Cons
- The transfer gear adds height, so many copies sit slightly thicker than the reference
- Running seconds can stutter or stop if the module is poorly assembled
- Costs more than quartz builds and needs servicing sooner
Use case: Buy this if the watch is going on your wrist as your main dress-casual piece and you care about the dial being right. It is the pick for anyone who has handled the real thing.
Runner-up: mecha-quartz or quartz build for daily wear
A quartz or mecha-quartz version uses a battery movement with a quartz chronograph module. The seconds hand ticks, which is an instant tell to anyone who knows the reference, but the case and dial can still be well made, and the watch will keep time without fuss.
Pros
- Accurate timekeeping and near-zero maintenance
- Lighter and often slimmer than automatic copies
- Lowest entry point in the replica tiers
Cons
- Ticking seconds hand is the most obvious giveaway on this model
- Chronograph pushers often feel hollow and the reset snaps hard
- Case finishing is usually a step below the automatic builds
Use case: A sensible choice for a beater, a travel watch, or a first purchase before committing to an automatic build.
Skip: the thick automatic with seconds at 9
Some sellers ship a plain 7750 in a Portuguese-style case and call it an IW371701. The subdials land in the wrong place and the running seconds sit where the chronograph minutes should be. No amount of dial printing fixes that, and the case is usually several millimetres too tall. Walk away.
Criterion: dial and handset
This is where most copies are judged. The subdials should be slightly recessed with fine concentric rings, not flat discs. The leaf hands should taper to a point and be rhodium finished, not painted silver. Check the date window: it should sit close to the 3 o'clock marker with a clean aperture, and the numerals should be applied, not printed. Look at the spacing between the two subdials and the centre pinion; uneven gaps are the fastest tell.
Criterion: case, crystal and caseback
The reference has a slim polished bezel, brushed case flanks and a domed sapphire with coating on the inside. A flat crystal with a heavy blue tint looks wrong in daylight. The caseback should be sapphire with the movement visible, and the rotor and bridges should carry some decoration rather than bare metal. Lug width around 20 mm matters too, because a strap that overhangs the lugs ruins the profile.
What to check when the watch arrives
- Start the chronograph, let it run five minutes, then reset. The hands should snap back to zero together.
- Watch the small seconds at 6 for a full minute. Any stutter or skip points to a weak transfer gear.
- Check the crown positions for winding, date setting and hacking without grinding.
- Look at the dial under a bright light at an angle for dust, misaligned markers or uneven printing.
- Confirm the case thickness against the seller's stated figure; a 2 mm overshoot usually means the wrong movement.
Bottom line
For most buyers, the automatic 41 mm build with a tested seconds-at-six module is the one to order. It gets the dial right, which is the whole point of a Portuguese Chronograph. Choose quartz if reliability matters more than the sweep of the seconds hand, and skip anything with an unmodified 7750 layout no matter how good the photos look.