Origin of this knife?

[fernando]

HI Rob T
You might try this aproach.
A Venenoza, correctly spelled A Venenosa, meaning The Poisonous ( Venomous ) One. Not a knife mark, but one of these popular phrases usually seen on blades. The z sounds the same as the s, and was used in an earlier period. The term is the same in spanish, but maybe the z letter apoints to old fashion Portuguese from Brazil or Brasil.
Just a hint.
fernando