Louie, I probably didn�t explain it well, but I agree with Manfred that you have to go down to bare metal to permanently stop corrosion. Either mechanically or chemically - and go from there. That is what makes it so difficult to deal with on period items where corrosion has taken hold.
Where it might get a little interesting with sword or dagger scabbards for instance is with any pitting that might be present. Specifically with pitting under a finish, which could give away the fact that an item has been redone on the blue/brown oxide finished ones and to a lesser extent with the painted ones. But I imagine that if an item wasn�t too bad and was repolished it might not be as obvious. However - with pitted fittings I think it�s going to be more of a problem especially if it's deep.
Manfred, Cyanide is used in some of the commercial/industrial processes which with current EPA regulations does make life more interesting.

When they cleaned up the old �Skunkworks� in Burbank it took a while and the site did create some well water problems locally. In Germany in the 1930�s industrial waste was a non-issue. Dumping effluent now will not only will get you into some major hassles but is going to cost you.
Nickel (or chrome over nickel) on top of zinc is probably the most common form of electroplating seen. In the home, automobiles, etc. If you don�t nickel plate using Texas Platers - is it because it doesn't work or you don�t like the results? Also, I�ve never seen the results from brush plating. Is it as smooth/even as commercial plating?
Regards to All, FP