You'll be hard pressed to return the blade to original condition. Instead, a brushed or bead blasted look would be easier.
Scotchbrite pads will give a blade a brushed appearance, and this will hide alot of scratches.
Deeper scratches could be hand-sanded out with wet/dry paper used wet, and a polish accomplished with higher and higher grits, finishing with jeweler's rouge on paper....
If you had access to a belt grinder, a fine grit would remove the marks in short order....
What sort of tools do you have access to? How much time do you want to spend?
J