The short answer
IW329048 is a 40mm IWC Pilot's Watch, part of the same case family as the Mark XVIII. The replica worth buying has a 40mm steel case, a properly decorated automatic movement, and a dial with the right numeral font and a date wheel that matches the original's shape. Expect to pay $280 to $450 from a mid-tier or top-tier factory. Under $150 you are looking at a different watch carrying the same name in the listing.
What the reference actually is
The 3290 block covers the Mark XVIII and its variants. That matters, because sellers mix dials and references constantly, and a listing for IW329048 will often show a Le Petit Prince blue dial or a bracelet variant that belongs to another number. The specs to hold in your head: 40mm steel case, about 11mm thick, 20mm lugs, soft-iron inner case for magnetic protection, 6 bar water resistance, sapphire with anti-reflective coating on both faces, and caliber 35111, a modified Sellita SW300-1 running at 28,800 vph with roughly 42 hours of reserve.
Those numbers are your checklist. Any listing that contradicts them is either a different reference or a seller who does not know the product.
The three tells that decide a good copy
Movement
Open the back and the story should hold up. The better copies run a Sellita-based automatic or a well-finished Miyota 9015 with a decorated rotor and correct engraving. Cheaper ones use a generic 21-jewel unit with a rotor that reads close but not right. The difference shows in two places: how the seconds hand sweeps, and how the crown feels when you set the time. A gritty, loose winding action on a watch at this price is a red flag.
Dial and date
The numerals are the giveaway. On the original the type is thin, evenly spaced, and consistent in weight. Copies often run heavy, or narrow on the 6 and the 9. Look at the date window: the aperture should be crisp with square corners, the wheel white with black print, and the font close to the dial numerals. A date sitting low in the window or floating high is common on budget builds. Lume is the other check. Charge it under a lamp for thirty seconds and compare hands to numerals. If the hands glow brighter or greener, that is a mismatch.
Case, crystal, and finish
The case flanks should be brushed with polished chamfers that catch light in one clean line. Some copies polish the whole flank, which reads flat and cheap in daylight. The crystal matters more than people expect. The original has strong double-sided AR, so the dial looks near black at an angle. A copy with single-sided coating gives you a grey haze instead. The soft-iron inner cage is usually missing or swapped for a plain steel ring, so do not count on the antimagnetic behavior of the real thing.
What I check when the watch arrives
- Timekeeping over 24 hours, worn and then resting crown up.
- Date change, near midnight and centered in the window.
- Crown threads. Screw it down a dozen times and feel for catching.
- Lug fit with a 20mm strap or bracelet, looking for gaps at the end links.
- Weight on a kitchen scale, since a hollow case back and a missing inner ring show up there.
Price tiers
Under $150: stamped movements, flat-looking printed dials, and crystals with weak coating. Around $200 to $280: decent case work, a serviceable movement, an obvious date font. $300 to $450: the range where dial printing, crystal, and movement decoration hold up in hand and on the wrist. Above that you are paying for a factory name or a bracelet, not for a better watch. If a seller cannot tell you which movement is inside, walk.
One last thing
Buy the version you can wear. A 40mm pilot watch with 20mm lugs takes any strap you own, and that is half the appeal. Getting the reference number right matters less than getting a case that sits well and a dial you enjoy looking at, because nobody is inspecting your wrist under a loupe. You are.