Parker Repros are not Cyanide colored. In fact they are not color hardened at all. They are made of modern steel, not requiring case hardening. The colors on them is actually a sort of stain applied to the metal to replicate the look of case coloring. The color will come right off easily with chemical stripper.

I have had a few Repros bone charcoal colored (by Turnbull) and the results were excellent. Just like any original parker.

The tang screw bridge on Repro trigger plates is a separate piece that is soft solderded in, not brazed. All you have to do is tack weld the four corners of it down before coloring and it will stay put through the process.

B.Dudley