Hello,
I think that there are several reasons that nobody comment until now, one reason could be seen in the somewhat dark pictures. Really old balato swords from the headhunting time are very rare and most of the time you have to pay a lot of money for them.
But balato swords has been in use until now for ceremonies (for tourist and also for real ones), I think that your one will be from the middle (a little up and down could be possible) of the 20th century, difficult to say from pictures only if before or after WWII, who will say it exactly?
The thick blade is a good sign, for sure a better later example.
Regards,
Detlef