Thank you Jens.
I will take note on the age.
This is what i could capture, with day light and strong sun shining ... a frequent event over here, even diring winter

. These blank parts could be because they were oiled or greased more than the rest, so they didn't oxide ... i don't really know
I will anxiously wait for your coments.
Thank you David.
I don't think there's any steel activity like wootz or the like, in this blade
Will these pictures define the situation to your eyes ?
Please tell
Fernando