Quick question about wear on ref. and case numbers between the lugs

[swish77]

Loose end pieces on the bracelet are the culprits. Over the years, even slightly loose end pieces can rub and rub and rub that area, taking off parts of the numbers. The rub marks are usually a very distinctive shape, almost like a half moon, because the end pieces are curved, of course. However, properly adjusted end pieces on a non-SEL bracelet shouldn't do this. On older watches those end pieces just have a tendency to loosen up over time and often they become slightly bent. At an RSC service, the tech will either adjust the end pieces or just replace them. So, worn areas between the lugs can also be an indication that a vintage watch wasn't serviced much, or that someone wore it a lot.