Nihonto Club

Hmmm, this afternoon I wrote a longish reply, that didn't seem to "stick".
The gist of it is this:
The blade appears to be severely damaged by sandpapering.
My recommendation is to arrange to show it (in person) to an experienced collector.
Here is a possible list of clubs, in case you are near any of these cities:
https://www.japaneseswordindex.com/swordgrp.htm

Pete

I see a Chinese counterfeit ...