When every single component of a timepiece gets swapped out over time, where's the line? At what exact moment does it stop being the original watch?

In the secondhand watch trading market, this philosophical puzzle becomes very real and very messy. Dealers, collectors, and brokers simply cannot reach consensus on where to draw that line—and the disagreement is wreaking havoc on pricing, authentication, and fair trading practices across the entire industry. Some argue the case based on movement, others on the dial, still others on the case back. No unified standard means chaos in valuation and trust.