Howdy DD...
Thank you for posting these images of this fascinating - and beautiful - dha variant. The hilt is most definitely made in the style of an ito-wrapped tsuka, and it is the first time I have ever seen this feature borrowed by and incorporated into another culture's indigenous weaponry.
I also agree the blade is not nihonto, but rather is a local interpretation of a katana blade. By your estimation, how old is this dha?
David: Interesting find, and thanks for posting it... You wouldn't happen to have a photo of that long hilt, would you? As it so happens, the curator emeritus of that collection is involved in the discussion of this piece over at NMB. He's about to leave on vacation but has said he is going to take a picture of another 'pseudo-naginata' in the Royal Armoury Museum when he returns... I'll ask him about the piece you're speaking of.