I was able to obtain two daos from Arunachal Pradesh. In this federal state of India living approx. 100 ethnic groups and nearly all have daos as their weapon and I think that it will be very difficult to determine the exact origin of this two dao. It was stated in other threads that this are Naga daos but when I read correct you can say only about one of this ethnic groups from Arunachal Pradesh that they belong to the Naga "family".
For Arunachal Pradesh see here:
http://en.wikipedia.org/wiki/Arunachal_Pradesh
One of the both seems to be nearly unused while the other one shows a lot of use. Here the both side by side.
A great thank and compliment to Robert for the excellent pictures from the both swords.