I have seen a couple of bikes outfitted similarly to the Violette. They were called "Desiree," and sold by a bike dealer (don't remember the name) in Santa Barbara in the late 50's or early 60's. What rings the memory bell is the wide range chainrings, remanufactured front derailleur, and helper spring for the rear derailleur. Not around bikes long enough to have seen these as new machines; these were bikes I worked on in the 1980's and 1990's, they just had drifted into the Portland area with separate owners. The frames looked much more French than Italian, with Nervex Legere lugs. I do remember the bike dealer being described as very eccentric, and trying to talk one bike owner and his spouse into attending his swingers' party!
David Feldman Random crap floating through memory in Vancouver, WA