Short answer
IWC reference IW371410 belongs to the 3714 reference block. That block covers the Portugieser Chronograph, the watch IWC sold for years as the Portuguese Chrono-Automatic. The suffix changes the dial color, the hands, the strap, and sometimes the case metal. IWC's own reference list is the source to confirm which parts IW371410 uses, because one number block covers dozens of variants.
The closest watch to it is the current Portugieser Chronograph in the IW3716xx block. The dial layout is the same: a 30-minute counter at 12, small seconds at 6, no date window, thin bezel, printed minute track. Both use applied numerals and dots.
Specs to compare
- Case: 40.9 mm steel, sapphire crystal, water resistance 30 m.
- Layout: two registers at 12 and 6. No date.
- Caliber: 79350 on older refs, a Valjoux 7750 base. Caliber 69355 on refs from 2020. Both beat at 28,800 vph. Power reserve sits in the mid 40 hour range.
- Caseback: display back on the versions IWC sells with the 69355, so the rotor engraving and bridge finish are visible.
Watches with the same two-register layout
- IWC Portugieser Chronograph IW3716xx. Same case size and dial, in-house caliber 69355.
- IWC Portofino Chronograph 39 mm. Same 12 and 6 registers, but adds a day and date window at 3.
- IWC Pilot's Chronograph 41. Same two registers, date at 3, wider bezel, soft-iron inner case.
Chronographs outside IWC use a 12 and 6 layout too, but most add a date at 3 or a third counter at 9. Those two changes are the fastest way to sort a lookalike from a match. Compare the case side profile and the lug shape before the dial, because dial printing is easy to copy and case geometry is not.
Checks that show a fake
- Subdial spacing. The 7750 family sets the distance between the registers. A clone movement with the wrong base puts the subdials too far apart or too close to the center.
- Dial print. Look at the weight of the numerals and the spacing of the minute track. Copies use thicker strokes and uneven gaps.
- Case profile. The Portugieser case has a narrow bezel and short lugs. Many fakes use a taller case and thicker lugs to fit a cheaper movement.
- Movement. A decorated 7750 or a Seagull ST19 sits in the low and mid tier copies. The 69355 has a different bridge shape and rotor engraving.
- Strap and buckle. Real alligator has visible scale edges. Stamped leather grain does not.
Price bands
A steel Portugieser Chronograph on the secondary market runs in the low four figures to high four figures in US dollars, with box and papers at the top of that range. Replica listing asks run from about USD 150 for a quartz or basic automatic build to over USD 800 for a copy with a decorated 7750 base and a sapphire crystal.
Unknowns and limits
IWC does not publish a full historical reference archive. If a seller cannot show a photo of the caseback engraving and the movement, treat the IW371410 claim as unverified. Match the number, the dial variant, and the caliber date to the same production year before you compare anything else.