Dear Pudgy:
Since I am just an amateur but a professional researcher, I can only give you some conjecture about Paiwan bead.

First, frankly speaking, all of my Paiwan beads came from trade but inherit. Most of them came from a Paiwan chief family member. Of course, I paid a lot for them, and I also asked him stung them into traditional body decorates style.

Second, according to that chief family member statement, somebody had found these beads in abandon long-house site in the mountain area of southern Taiwan. But, he also reminded me that some real supernatural stories about digging those archeology site. We believed that if you get paiwan bead without permission (Sorry I cannot use the correct word in English), its pre-owner will come into your dream every night. And, it really happened. As the result, lots amount of Paiwan beads were preserved safely somewhere in Taiwan.

Third, I think I have found a special character indicating that all Paiwan beads (different to those Islamic trade beads and Venetian beads Paiwanese collected also) had been made in a limited small area. Not southern Taiwan but Borneo Island. I wish I can have more time find some strong evidence holding my opinion.

Fourth, Paiwan bead have been a name of tourist souvenirs recently, those shining fragile new-made beads only imitate old beads appearance. For example, reproduction cannot (or does not want) be made the same with the dark and red one on the top line of the choker I shown.

I hope I have answer all of you questions, best new year wish to you and your family.

Sincerely
Wayne