I wondered, could this perhaps be from the Philipines? Both the talibon and pira have a similar 'oddly' shaped blade with its downward curve preceded by a short straight section.
Then I found the following description here:
http://home.earthlink.net/~federicom...roweapons.html
"The Pira has a thick falchion shaped single edged curved blade. The handle normally has an upcurving horn, and is often made of various native hardwoods or horn. However like all Moro swords there are exceptions. Primarily a fighting weapon it is favored by those within the Sulu Sultanate, particularly the Yakan. However more modern piras have evolved into a plainer work oriented blade, with a simple hilt lacking the decorative horn."
Could this be one of these plainer work oriented blades and does anyone have examples to compare with?