I’d start with a high‑resolution scan of the original gear train, then use CAD to create a detailed model. After that, I’d prototype each component with a CNC mill or 3D printer using the exact material the original used—maybe a brass alloy or a low‑temperature hardened steel. The key is to keep the geometry identical so the hand‑feel and gear mesh stay the same, but I’d replace brittle wooden pins with miniature stainless‑steel pivots to reduce wear. Then, I’d apply a thin, non‑reflective finish that preserves the antique patina but protects against oxidation. That way the engine looks as it always did, runs as reliably as a modern watch, and still tells the same old story.