Quick answer
A fake Portugieser Automatic gives itself away in four places: the power reserve hand, the case thickness, the dial printing, and whatever you can see through the caseback. I check those in that order. Get them right and you are looking at a serious copy. Get them wrong and no amount of box candy fixes it.
One thing worth saying up front: selling counterfeits is illegal in the US, and customs can seize imported goods. Buying for personal wear is a different risk than reselling, but the risk is real either way.
The power reserve hand
The real watch runs a seven-day movement, so the reserve hand at 3 o'clock sweeps a wide arc and tracks how much wind is left. On most fakes that hand is decoration. It jumps with the rotor, sits near full when the watch is dead, or travels an arc that means nothing. Wind the crown 30 turns, set the watch down, and look again after a day. If the hand has not moved, or moved the wrong way, you have your answer.
Case size and thickness
Know the reference you are comparing against before you judge anything. The 42.3mm Portugieser Automatic stands about 14mm tall, and that height comes from a tall movement. Copies built on a thin quartz or a small automatic end up flat. Copies built on a cheap automatic often go the other way and sit 2mm too thick, with a caseback that bulges past the lugs.
Calipers are better than a ruler, and a ruler is better than nothing. Then look at the lugs. The real ones taper and curve down toward the wrist, and that curve is difficult to copy well.
Dial work
- Applied numerals should sit proud of the dial with crisp edges and a polished bevel. Glued or stamped numerals look flat under a loupe.
- Feuille hands should be thin, leaf shaped, and evenly finished. Bent tips and patchy polishing show up fast.
- The subdial at 9 should be recessed with its own texture. A painted-on subdial ring is the classic tell on cheap copies.
- Printing should be sharp at macro distance. Fuzzy edges mean sloppy pad printing.
Movement and caseback
An exhibition back is a gift to a buyer. Look for a Pellaton style winding system, Geneva stripes running in one direction, screws that are actually blued steel rather than painted, and engraving that is cut rather than laser etched in a dot pattern. Generic rotors with the wrong text, or a jewel count that does not match the movement the dial claims, are common.
Feel in the hand
Winding a seven-day movement takes effort. If the crown spins free and the watch is running after five turns, the movement inside is not what the dial says. Each crown position should click in firmly. The strap should be thick, the buckle should have weight, and the spring bars should not rattle when you shake it.
Price as a filter
The genuine watch costs five figures. A first copy at a few hundred dollars is a different product, and it should be judged on its own terms: how it looks on the wrist, how it keeps time, how it holds up after a year. Do not expect an in-house seven-day movement at that price, and be suspicious of anyone who tells you that you are getting one.