From a perspective of a builder... the dropouts on this and the Origin8 were not specifically designed for the triple stays on a Mixte and this one is confused as it has a socket at the chain stay but does not have one for the seat stay and the middle stay is just tig welded into place.
The Peugeot has a less ornate stamped dropout made from relatively thick plate and was made specifically for a mixte frame... not quite as pretty but it is simple clean work done when mixte frames were not boutique items but just a very popular type of bicycle that is once again becoming popular.
With the great number of older mixte frames out there one could consider buying one of these and refitting it as needed... had a nearly identical Peugeot roll in and out of our bike co-op a short time ago, it was nearly mint and did not last very long at all.