IF it is still in knife form (has the handle and guard on it) then you can put the blade in cider vinegar and see how much it helps. If it was amde with simple alloys, this will often "freshsen up" the pattern a good bit. If you have taken the handle and guard off, then you have a lot of options to get the proper etch on it. Degrease the blade with denatured alcohol or acetone and then wipe cider vinegar on it with a clean cotton ball.

skunk out