If the pitting is not severe and you have the parts nicely cleaned, have a go at cold bluing. Maybe not as good or durable as a professional reblue... but pretty cheap. I have done this on old actions that a previous owner has painted grotty black; Cleaned parts down to 600 or 1200 grade paper then degreased etc and cold blued applied a few times as per instructions. I was surprised to see that after a few applications the odd pits I had seen were disappearing. Keep at it ... it should work. Preparation is the key to success.
Cheers, Phil