Hello Séverin,
Agree with Kai, it's a coteng! Very good find! The scabbard is typical Coteng form and undamaged, and the hilt can get restored with some skill and I agree again with Kai that this is most probably a former local repair, look here:
http://www.vikingsword.com/vb/showth...ghlight=tajong
When you compare with pictures from Conteng hilts it will be possible to carve a fitting nose for the hilt.
The blade looks Javanese or possibly Sumatra to my eyes, difficult to say because it's a very worn blade, also not unusual for a Coteng, the blade could come from everywhere. The gonjo seems also to be a replacement.
The base of the hilt is repaired, I wouldn't change that. I just would give the hilt a new nose and would clean the blade in a vinegar solution, the varnish I would try to remove, and you will have a very nice Coteng keris!
Regards,
Detlef