My favorite smell is the fragrance of the Joshua Tree forrest I live in after a light summer monsoon. If they made it into a perfume I would wear it. It is sweet, a hint of musk, with a beautiful fragance . Very hard to describe.
The way you describe those mill towns reminds me of growing up in Torrance California. There was a huge plant that was Farmers Brothers as I recall that emmited this rank putrid stink. I would always think, how could making coffee smell that aweful.