Joe, I'd guess you are correct that the 18th century mill was water wheel driven, but I think the larger drive gear is part of a very old technology that is being reintroduced as "new and superior". Google Tsubaki Pin Gear, or just Pin Gear and you'll see what I mean.

As they say, "nothing new under the sun."

The coupling of the rolling mill stand to the slitter stand suggests that even this mill process had evolved over time from something even simpler.

A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.