8MM/06 I tried the blue wonder thing waste of time and money I needed to refinish a military floor plate ,I call them the company there statement could be the metal on the A3-03,gave up.
I've had pretty good results with Blue Wonder. There are some alloys that don't work as well with it, likely your floorplate was one.
Blueing doesn't cost much at all, prep work is what you pay for.
Laurel Mountain Forge's browning solution will convert to blue with boiling, too.