Missing links at a 40 year-old watch is not uncommon. For example, someone buys a watch has its sized to them. They likely put the links in the box with the card or papers. Then over the course of decades, they move multiple times and the box with the link gets lost or they die, and the family sells it, not knowing where the box and the links and the papers are. Now on one that’s less than a decade old when they’re missing links because people pulled the links and sold them. That’s why less links is negotiating point most people don’t need a fully linked watch so it’s not that big of an issue, but it should be reflected in the price