How about the forked stick idea, only taking a straight stick, and putting a notch in it, and then putting the point in that notch, and then taking two sticks, with straight grooves on one side, and putting those on the edges, and then lashing, and or gluing the sticks to the main stick, with the point in it. ?
Just a thought, if you can't find the "right" forked stick, make one.
I just wish I could make a blade like that, never mind the cumberland, or any particular style.
That is nice work.
Wayne