Xeney,
Pretty interesting; what isn't lugged on the maroon mixte?
The steel components on my maroon "look" original.I would bet the black cloth tape is original. Of course, the parts could have been switched out, but since the 1983 came with steel wheels/handlebars, I kinda think that more likely that it is 83 or earlier.
On the lugs-mine has lugs "everywhere" ;even the long skinny double top tubes are lugged in the front and middle. It would have been cheaper just to sorts tack weld them like a seat stay, but they have two tiny little lugs protruding from the head tube top lug.They are lugged in the middle support also.
The lugs are pretty clean-not bad for simple,cheap lugs.I guess they are cast-or can they be stamped out and welded?
Let us know about the non lugged components.Seems like the late 80's was when lugs "died" on bikes.
Thanks,
Charlie