Jason,
Wish you were right.....
No, there is no chance this blade was made my Masamune, Muramasa or even the most undistiguished Japanese smith
This is a product of a very primitive village foundry, far, far away from Bizen...
No sense disassemmbling it.
The tsuba is , as you say, reminescent of a Japanese general geschtalt, but is definitely NOT Japanese either: its core is soft metal ( copper? I seem to see some reddish hue) and is clad on both sides with another metal that even peeled off the base. The decorative motives are pretty basic and technically simple over the weekend I shall gently clean them and see what transpires.
Hope to find an inscription " This belongs to Mr. Pol Pot. Pretty please do not touch. Or else...."