Back in the day , the 60's , most high end bikes I remember had Nervex pro lugs , Masi Specials both road and track , Mondias , Uragos , Schwin Paramonts , I recently saw a photo of a Cinelli with Nervex lugs . Granted most Italian bikes used other than Nervex lugs . I do remember a lot of Paramonts with real sloppy finish work on the lugs . I think their going out of style was economic rather than difficulty in brazing , it just takes a lot of time to prep them for use . I do silver brazing on scientific equipment and can appreciate the skill level of journeymen frame builders . Jim McCoin