Thank you all very much for your kind words and thoughts on this most interesting, unusual and probably rare item. If it is the consensus that my latest treasure (even though not an actual weapon) was most likely used as a ceremonial rice harvesting knife I couldn't be happier. As we all know anything can be used as a weapon, but to me finding the original intended purpose of an item such as this is much more important. I now hope to someday find a photo or drawing of another example of this knife (or at least very similar) with a description of its use or (if you are going to dream you might as well dream big) an old photo showing one actually being used.
My next project will be trying to find someone who can identify what animal the bone being used as a guard was originally from. I have now had two individuals suggest that there is a good chance that it could be human.
Personally I would prefer to find that it is from a water buffalo instead. Any other comments or suggestions on this piece would also be greatly appreciated.
Best,
Robert