Thanks! Yes, I found that page as well. It seems Cogolo licensed or built several factories across Europe, and I guess their method was included in the package. I found an Italian court document about the foreclosure as well but it only gave me dates.
Tbh, I love doing this kind of research. It contains nuances of history and knowledge that is hard, or even impossible, to gain through normal education. I almost even sent an email to a person with a PhD covering "tanning culture" but quickly realized the topic was more "tanning bed" and less "tanning vat"