[hrbla]

For selective areas, I am planning on DIY metal work to lighten the surface pitting and rust blue it after that. Several thoughts rised up while deciding the course of actions as following which really appreciated for your experience inputs:

1. Is it ok (in terms of shooting safety) to rust blue inside the barrel? Will it help to lighten the pittings at the grooves and lands and improve accuracy?
2. For partially rust blue on areas, would you recommand to remove all the original blue before applying the new? or just leave the old and let new/old to mix/overlapping?
3. For trigger and several others, I been told that they were surface hardened steel (no blue) and patina formed on the surfaces throughout the years. Would you suggest a way (I like anlanint's idea on brass brush for rust, but is aggresive) to clean them without removing the patina?
4. I wonder if any fellow collector here might have a "byf' luger with Erfurt toggle train. We may exchange to make both satisfied. To this proposal, where would you suggest me to post?

Thank you in adance for inputs!