It may be a prestige, really don't know. But even if yes the simplex plastic is not really good and tend to break I find those derailleur really easy and quite smooth to use, most of the time I broke the front one (the clamp to the frame is really really bad), never broke a back derailleur (but I am not a prolific rider). The simplex on this bike is quite nice looking, I love the logo and the gold color.
Anyway I think I am gonna clean the bike as best as I can, all the parts have been cleaned and works great (I really love those weinmann brakes, have some Mafac in France which I love and really wonder how those are gonna brake !).