Thank you for posting.
Nice blade indeed. The handle is simple, but not bad at all.
Here is another threads showing a very similar blade attributed to the Baram area, Sarawak.
http://www.vikingsword.com/vb/showthread.php?t=14272
The blade is a mandau blade with a concave/convex shape. if they are decorated they are always less decorated on the concave side. often the concave side is decorated near the handle, as yours is.
Nice piece, congrats !
Best regards,
Willem