If I might offer an observation in a somewhat humorous light ; when you get down to the split the blade looks 'too light to fight , and too thin to win'.
I would think that if one were lucky enough to get a blade trapped in the split area and tried to twist it out their opponent's hand they might well end up with two very unaligned points ; the area (IMO) lacks 'beef'.
I just wonder if this is an old hilt married to a newer blade and meant to be brought back from Indja with a Britisher during the late 19th .
As a matter of fact I'm doubting any of this piece is "17th C."