Kaskara with unusual patterning in the blade

[katana]

Hi,
this Kaskara seems to have a very crude wootz-like pattening all over the blade (the pics do not show this clearly). Excellent temper and the edges are still quite sharp even though it was quite rusty. The blade is approx 4.5mm at the forte and the central fullers are forged....rather than ground.

I am not suggesting that this blade is made from some sort of course, wootz billet, but there is 'something' unusual. There is a 'bright' and 'dark' grainy effect as if there are two different grades of steel/iron. I wonder whether it is 'shear steel'. I remember reading somewhere that blades made from 'shear' were considered high quality.....but I cannot find the reference Evidence of re-sharpening of the blade....sometime ago. No markings.

I believe the blade is much older than the hilt (re-hilts are extremely common due to climatic conditions) The cross guard also has age.

Any and all comments gratefully received, thank you.

Regards David