Buy the movement first and the dial second. On a first copy of the IWC Portugieser Chronograph IW371470, the detail that decides whether the watch reads as convincing at arm's length is what sits under the dial: a working 7750-type automatic chronograph with running seconds in the subdial at 6 o'clock and a 30 minute counter at 12 o'clock. Case finishing, crystal clarity and strap quality all show up in photos, so they can be judged before you pay. The movement cannot. Ask for a short video of the chronograph starting, running, stopping and resetting to zero, plus a clear look at the case back, before you send any money.
What to look for in a first copy IW371470
- Subdial function. The small seconds at 6 should sweep in a smooth arc. The counter at 12 should step once per minute while the chronograph runs. A seconds hand that ticks once per second is quartz, not the 7750 layout.
- Chronograph feel. Pushers should have firm, short travel with a clean click. Reset should snap the central hand back to 12 with no creep or overshoot.
- Case back. This reference uses a sapphire display back that shows the movement. A solid steel back on a listing that claims an exact match is a red flag.
- Dial furniture. Applied numerals and leaf hands in gold tone on the silver plated dial, a printed minute track that holds up under a loupe, and a date aperture cut clean with no burr around the edge.
- Case profile. Flat bezel, straight lugs, brushing on the flanks that runs in one direction, polished bevels that match on both sides.
- Strap and hardware. 20 mm lug width, stitched leather with a signed tang buckle or deployant, spring bars that seat without rattle.
Movement choices and what each one tells you
The genuine watch runs IWC calibre 79350, a reworked Valjoux 7750 with a 4 Hz balance, about 44 hours of reserve and the counter positions rearranged to suit the Portugieser dial. A good first copy uses an Asian 7750 clone built to the same layout, which is why the subdials land in the right places and the chronograph behaves like the original. A cheap copy either drops in a quartz module with decorative subdials or uses a 7750 with the wrong subdial spacing and a date wheel that sits off centre.
Ask the seller which movement is fitted and treat a vague answer as a no. A 7750 based copy is heavier, has a slight rotor wobble when you rotate your wrist, and shows a stepped, mechanical reset. That behaviour is easy to film, so a seller who will not film it usually has something to hide.
Parameter bands to check when the watch arrives
Measure with calipers rather than trusting the listing. These ranges describe a copy built on correct proportions:
- Case diameter: 40.8 to 41.1 mm across the bezel.
- Case thickness: 12.2 to 13.5 mm. Anything much thicker points to a tall chronograph module stacked on a thin base movement.
- Head weight: roughly 60 to 75 g in steel, before the strap. A head that feels light for its size suggests a plated alloy case.
- Lug width: 20 mm at the case, tapering to a buckle around 18 mm.
- Water resistance: the original is rated to 3 bar, which covers splashes only. Do not swim with any copy, whatever the case back says.
- Crystal: flat sapphire with a light dome and anti-reflective coating on the inside.
Pitfalls to avoid
- Stock photos of the genuine watch used across several sellers. Ask for dated, in-hand macro shots of the actual piece.
- Listings that never show the case back or the movement running.
- Payment methods with no recourse if the watch arrives with a dead chronograph.
- Claims of Swiss origin on a watch in this category. The movement will be Asian, and a seller who says otherwise is not being straight with you.
- Ignoring the date change. Set the date through a full cycle and check that it flips cleanly at midnight rather than dragging.
A first copy is a replica, not a genuine IWC, and it should be bought and worn as one. Judge it on the quality of what you receive, not on the story attached to it.
FAQ
Is the IW371470 the same as the current Portugieser Chronograph?
It belongs to the same 3714 family and shares the 40.9 mm case and twin counter layout. Dial colours, hands and strap options vary by suffix, so confirm the exact variant you want before ordering.
How can I tell a 7750 copy from a quartz copy in photos?
Look at the subdial at 12. On a mechanical copy it advances in single minute steps and the central chronograph hand sweeps. On a quartz copy the small seconds tick once per second and the pushers feel soft.
Should the case back be see-through?
Yes. The reference has a sapphire display back, so a solid back is a mismatch even if the outside of the case looks right.
Will a copy take a genuine IWC strap?
If the lug width is a true 20 mm and the spring bar holes are drilled at the correct height, an aftermarket or original pattern strap will fit. Check the fit before you wear the watch hard.