References are not interchangeable
Some manufacturers combine movement and case codes in a single engraved marking. A dial reference can differ from the external case reference; a serial number can describe a physical case rather than a movement.
Photograph in context
Capture the entire back, a straight-on crop of the text, crown orientation, bezel, bracelet attachment and any maker's logo. Never rely on a single blurred number.
Red flags worth documenting
- Caseback code that does not match expected case construction
- Dial printing inconsistent with the reference family
- Movement replacement indicated by conflicting stamps
- Tool marks or polishing that obscure original engravings
Such evidence prompts more research. It does not alone prove deception.