Dan,

You can probably “bring up” the etch using wet-or-dry sandpaper on a FLAT (
emphasis added! ) hardwood block using WD-40 as a lubricant.  Lay the saw on a
flat surface with the handle hanging over the edge.

Preliminary scrape with a single-edge razor blade gets off any flakes.

Galoots with “A Saw Problem” tend to buy WD-40, a.k.a. “The Galoot After Shave,”
one-gallon cans.

Evapo-Rust is pretty harmless, but won’t “bring up” the etch.  Acids and
electrolysis are potentially harmful to saw steel. Acid will erode whatever
surface and etch remain. Electrolysis can introduce hydrogen embrittlement
issues.

John Ruth
Hoping that everyone noticed the “after shave” reference coming after the razor
blade reference!