Mandau for identification

[Pertinax]

I cleaned the blade of dirt (without fanaticism), I will not carry out a deeper cleaning. After cleaning, a notch appeared on the butt of the blade.

The plane of the blade, concave on the left side and slightly convex on the right, is made for a right-handed person.

In my opinion, the item is quite old, I can’t determine it more precisely, my knowledge is not enough.