Some thoughts
 

Gavin et al,
These blades are not uncommon, although the point clipped that much is different, however Andrew mentioned the Kachin, the Chin did also clip their blades.
From a dealer who travels to the Burmese border regularly I learned that these were at one time worn by every male member of the hill tribes in northern Thailand and up into Burma and that you could tell which tribe they were from by the design used on them. Another dealer at another location stated the same even purported to be able to ID some of them by design (doubtful but possible) I have no other documentation to back those statements. Generally they have very poor quality blades, yours is much better than the average.

Including a picture of a Chin knife that I picked up from the one dealer as reference. While the scabbard is an open-faced basket type you can see the similarities in handle design and blade profile. Actually as I think about it there is distinct progression from the silver dha hmyuang through the knifes that Chris and Stuart posted and then to the Chin Basket knife. I wonder if it follows territorial boundaries?

Regards,

Dan

Problem solved
 

Thanks guys----have managed to locate source of Rayskin locally.
Appreciate all the help.