I'd thought the absolute upper limit for composition of the Pauline Epistles was 144, when, Marcion was excommunicated.
http://www.earlychristianwritings.com/marcion.html
I'd be interested in learning why that limit should be pushed to 180.
Who said Marcion was excommunicated c 144 CE?
The same persons who did not know when their OWN Paul really lived, what he wrote, and when he died!!
The same persons who made claims about Marcion did not know who wrote their OWN Gospels, when they wrote and their contents.
Just imagine that Irenaeus made all sorts of claims about Marcion but argued that Jesus was crucified about 20 years after the 15th year of Tiberius or about c 49 CE and under Claudius.
Irenaeus who supposedly wrote so much about Marcion did NOT even realize that if Jesus was crucified c 49 CE then the Gospels, Acts of the Apostles and the Pauline Corpus are historical garbage.
What a disaster!!
The very first writer to mention the four Gospels, Acts of the Apostles and the Pauline Corpus did NOT know that it was taught in the Churches that Jesus was crucified under Pilate in the reign of Tiberius.
Scholars have rejected almost everything that Irenaeus wrote about the authorship, and dating of the Gospels, Acts of the Apostles and the Pauline Corpus.
It is quite evident that claims that Marcion knew of the Pauline Corpus are late inventions. If forgeries were not manufactured then we would have had NO trace of the Pauline Corpus in 2nd century Apologetics.
It would have been obvious that the Pauline Corpus was unknown by 2nd century writers.
1. Hippolytus contradicts all claims that Marcion used the Pauline Corpus.
2. Justin Martyr claimed Marcion preached another God and another Son.
3. Ephraem the Syrian wrote three books Against Marcion and there is virtually nothing about the Pauline Corpus.