If you build anything around watch data — a marketplace, a valuation tool, an insurance

quoting flow, a collection tracker — you eventually hit the same wall: you have a

reference number (126500LN-0001, scraped from a listing or copied off an invoice)

and you need the spec sheet behind it — movement/caliber, case material, dimensions,

water resistance, dial color and finish. The listing itself never has all of this. Where