I never like to be quick on a verdict when it comes to non standard or unusual versions of weapons. Even in stones there are old kukries with tulwar handles. In northern Indian cross over happens. I think the handle and blade are a great match and each part are surley old. What I do have a problem with is the copper clout nail uesd to secure the handle. So I really hate to say it especially as I collect the odd stuff, this does not look right. You paid handsomely for this I would piont it out to the seller.
http://www.toolstation.com/shop/p84270