Peugeot Bottom bracket Threading
 

What year did Peugeot begin using British left hand thread (drive side).
How to identify a bike that has this threading?

Early 1980’s the transition began. By mid 1980’s, when the rainbow graphics appeared, the transition was near complete.

Aroung 1984/85 Peugeot banished French and Swiss BB threading, except for a very few Vitus steel framed bikes.
By 86 every bike pretty much had BSC threaded BBs, at least in the US market.....
Bad thing was, Peugeot simetimes used BBs on their low to mid model bikes back then (generic Stronglight) with no marking on them at all and sometimes figuring out what threading they had can only be done by removing them or looking at the threads that might be visible on the adjustable cup.

Don't forget Swiss thread (my 1980 PKN-10). Fixed cup was gold-colored.