I hope that any noobs who are still with us here will understand that, in some cases, we are dealing with aesthetics here. The brake bridges and bottom brackets above are good examples. All the example shown are perfectly serviceable; but many of us prefer the aesthetics and additional work put into the "better" examples.
Same goes for the much-quoted lugwork examples. Much more work and attention to detail went into the "good" examples but that doesn't mean that the "bad" examples are going to fail. Those small gaps under the lugs, while ugly to many of us, make up only a tiny percentage of the brazed surface. Indeed, the two bikes shown appear to have been ridden quite a bit with no failure of the joints. This sort of flaw is indicative of shoddy workmanship and hurried assembly but seldom means that the bike is going to fall apart.
Brent