This page has a pretty nice lineup in the way of lug filing to compare:
http://www.classiclightweights.co.uk...ts/nervex.html
Keep in mind that the Nervex Pro lugset was thick and usually finished like garbage in its raw state. Compare the 1955 Gillott with the '62 Viking. Hardly any smoothing on the Viking, and there seems to be a big defect at the back of the lug too (not typical, ignore it). The Gillott has had the lug filed down nicely - not too much, but well done nevertheless. The 1986 Mercian takes the cake over the Gillott however - notice how it has not only been filed to a beautiful, even thickness, the lower ridge has been filed smooth with the rest of the lug. Same for the '04 King of Mercia.
Consistency in braze around the joints is another thing - get a close look at the downtube lug on the Confente you've linked. Notice how the edge is sharp until it comes to the tip, where the transition between the lug and the tube becomes less blocky. Excess brass or silver is the problem.
Soon as I can find the photos, I'll post some random nasty lugwork from my '61 Paramount.
-Kurt