This interesting blade seems to have some genuine age and appears to be a remounted example of the hafted Chang dao of Assam (Rawson, p.58). Although Rawson describes these among 'modern' dao, that blade appears as noted to have some age, certainly 19th c. The 'fishtail' shape of the blade does have keen resemblance to the kora, but actually reflects the 'V' shape of the early dao known as the 'milemnok' used by the ancient Konyaks who were an early Naga people in Assam.
It would appear that this blade found its way to a modern hilt which I cannot positively place, but in any case seems a worthy old blade from Assam.
Most definitely unusual !!
Best regards,
Jim