[Sajen]

Some time ago I have acquired this very unusual bolo. On the first look you may think that it is a Visayan talibon but what is unusual that the edge is chiseled on both sides. So I want to ask you if you have seen something similar before and have a clue from where this bolo could be.
The length with the scabbard is just under 25". Blade length is 18 1/2". Widest point of blade is just over 2".
Like always are all comments are very welcome.