Hi all and thank you for your comments. On the Mandau: maybe from pictures it's hard to say but the blade is very nice and not crude at all with a beautiful inlaid work. I don't want to defende at any cost my piece but could be well that was collected early as the seller says:
"The sword brought to the Netherlands by a Duth captain of the KPM steam package service who died in 1934. His first journey was in 1887 according to his grandson" Maybe this piece never had taken heads, as Ben would say, but I think that is quite old (early 900 at least), but i'm not an expert.
For the handle: we see also good mandaus with completly undecorated hilts, but maybe this is not the case. Just thoughts for discussion