I revised one of the documents to cover the evolution of iron & steel components in pattern welded barrels
https://docs.google.com/document/d/1V-qkkHrs7yJakMkakxkiMx8FzJjGXUg0EDm8-_AQPiA/edit

Again, I have a crolle and a twist barrel segment for composition analysis

Strength & composition of vintage new fangled steel barrels is still here
https://docs.google.com/document/d/1dnRLZgcuHfx7uFOHvHCUGnGFiLiset-DTTEK8OtPYVA/edit