One queston I have regarding this Nitre Bluing process, will it affect any parts that are case hardened? I want to Nitre Blue the top lever, and it is case hardened.

I know the shaft is. I took a hammerless top lever and shaped it for a hammer gun. The top part was workable and to me I was able to file it with no problem and I don't remember if in the begining I had trouble breaking through the skin.

David