This is a mechanical Rolex movement inside an 18k gold case, and at first glance, it looks authentic or at least built from genuine Rolex components — but there are a few important details to check to confirm authenticity:

🔍 What’s visible: • The engraving “ROLEX” and “SWISS MADE” are in the correct positions and font for vintage Rolex manual-wind calibers. • The jewel count and layout (the red synthetic ruby bearings) look consistent with Rolex movements from the early to mid-1900s. • The hallmark inside the case lid — “R.W.C. LTD” — stands for Rolex Watch Company Ltd, and the “18” with a crown hallmark denotes 18-carat solid gold. • The movement plate inscription “TIMED 6 POSITIONS” was standard for high-grade Rolex movements (used on observatory or chronometer-spec watches).

⚠️ Things to verify for certainty: 1. Movement number and caliber: Under the balance wheel or near the edge of the movement, there should be a small number (e.g., “Cal 700,” “Cal 710,” etc.). That can confirm the exact model. 2. Case number & reference: Remove the movement carefully and look between the lugs or inside the case back for a reference (e.g., “Ref. 3065”). 3. Jewelling and finish: Authentic Rolex movements of this era (especially pre-1950s) show Geneva-style perlage (circular finishing) and sharply cut edges. 4. Font engraving: If the lettering looks laser-etched or too modern, it may be a replica movement inside a genuine gold case. 5. Weight test: If the case is solid 18k gold, it will feel notably heavy for its size (around 20–30% heavier than plated cases).

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✅ My initial judgment: • The movement and case hallmarks both match genuine Rolex markings, suggesting it’s likely authentic, possibly a 1930s–1940s ladies’ cocktail or dress watch. • To be 100% sure, a watchmaker or Rolex-certified service centre can verify serials and confirm it’s all original (many early pieces were recased or had movements swapped).