Complete guess work but there is some similarity to the native weapons of Formosa or modern day Taiwan. It might be a good idea to get in touch with our fellow member "yanchouming" "zanchouming" if that is the right spelling. There are not many members starting with a Y or Z so it is not hard.
This is the chap----yuanzhumin
Sorry I have just read the link thread and we have been down that road. Does not mean it is completely wrong.
