The research that you wrote about from that other site can be found on Hans Weilenmann's site at this link. http://www.danica.com/flytier/swilli...ispensible.htm
AlanB nailed it when he wrote that there aren't any magical properties about the scrotum hair on a ram, since the hair from that spot and the surrounding hair are very close once you get it clean. I'm not going to go too far into it, but every time a sheep is sheered, it's hair gets more coarse. The better hair comes from a ewe, the younger the finer. They throw out the belly and docking area hair since it's too soiled to clean easily. It would be FAR easier to get hair from a young yew to make the same type of dubbing since it would be finer and super easy to clean. The original Tup's dubbing was a dirty yellow, since it had yellow mohair instead of the red seal that G E M Skues suggested later on. Why the complete change in the original color since it caught fish? There's some big pieces in the history about it that are missing, but it is a good story, and supposedly he made a lot of money off of it.