The markings at the back of the blade also could be seen at the back of some Borneon pakayun blade whilst the hand guards are similar in the sense that they are both circular. If I remember correctly, both Ian and Andrew have mentioned the markings at back of the blade could be seen at other SE Asian swords. I've asked a number of Muruts for it's meaning but got no answer to date.
The blade is parang-like and some indigenous in SE Asia do have Chinese ancestory as the guy's features show. A more likely SE Asian candidate perhaps and a hybrid?
I've copied Mmontoro's pakayun pictures from another thread for reference.