Some time ago i embarked on a research project into the history of fly lines, the horse hair bit remained ellusive until i found a guy that made them and fished with them,
this guy fills a gap in fly fishing history in a very hands on way and was more than helpfull, the bit that sticks in my mind most was his description of what it was like to cast a horse hair fly line, not something you hear every day.
his name is paul and his website may be interesting to others that fancy a little historical trouting, he also sells things you just dont get anywhere else.
www.historicanglingenterprises.com