Pictured is a boxed set of Nervex Professionnel lugs which came complete as 3-pc. lugs, b/b shell and fork crown, made by Francolam SA, Saint-Etienne, France, who were specialists for pressed steel products ranging from high-class bicycle lugs to moped petrol tanks. Their 1958 catalog (reprints at velo retro) lists hundreds of items.
Professionnel lugs were one of a huge range of cuts. Their pattern numbers 49/162 (feature/nozzle) were reserved for the Professionnel series with the typical lips around the top of the top headlug and the bottom of the lower had lug. Other cuts from the less prestigious Série légère were less elaborate.
Looking at a raw lug one can easily discern where the weld seams are, and how the different processes of pressing and stamping transformed the original steel sheet. Nervex Professionnels needed a certain amount of fine tuning in the form of filing because they were partly hand made and shapes varied slightly. This is why they vanished when microfusion lugs became more widespread.
information from Toni Theilmeier
On the picture with three lugs we can see that the one in the middle has two thin horns in front; this is the first model. About 1956 it is replaced by the one on the left wich has a fishtail in front. The one on the right is a crude copy of the early design by the firm of Bozzi.