I bought this knife some time ago on ebay. It looked interesting. At that moment, a discussion on hudiedao was held on the forum.
In my opinion, this is also a hudiedao. The blade and handle are made from one piece, with a pommel and D-shaped handle attached to it. The handle extends on one side of the blade (back) and ends in what I call a 'snake's head'.
I don't see any holes in the tang to retain a handle of some sort. Could it be that the handle was made out of leather or some kind of fabric ?
The blade is slender and ends with a sharp point. The handle is aligned to the back of the blade. There's only 1 sharp edge and there are 2 fullers on both sides of the blade. There are also some engravings near the handle, but I can't make out what they are.
Total length : 49 cm (19,6 inches
Lenght of blade : 35 cm (14 inches)
Thickness of blade (near the handle) : 7mm