Hello Athanase,
you have there a rare gobang from Sunda, West Java. See here:
http://www.vikingsword.com/vb/showth...ghlight=gobang and here:
http://www.vikingsword.com/vb/showth...light=sulawesi
I personally would agree with your age guess. The lack cover will be from a previous owner, maybe shellack. In the upper part will has been a cover from red cloth but the less of the scabbard will has been covered with rattan. Nice catch!
Regards,
Detlef