Could OP's bike be one of those last gasp transitionary bikes that Peugoet issued in the mid 80s......just like my 84 PSV that was "gifted" by Peugeot with the oh-so-obsolete back then already, Swiss threaded BB! Almost like a joke that could become sick when I have to eventually pay mucho mullah to replace it with a Phil Wood Swiss threaded bb sometime in the future when the fixed cup finally wears out on it.
Chombi
84 Peugeot PSV
85(?) Vitus Carbone Plus 7