That features a rivet, the bolster isnt truly integral, ill post a kukri & some Karda in a few days that show some very similar features.
I think its NWF to Veitnam on horzontal travel, Southern China to southern Burma or Thailand on the vertical.
My real guess is Bengal/Assam/ Northen Burma....... small diameter ivory is Common , steel is at a preimium.
But nothing that makes the fat lady sing.....
Spiral