I have found over time that bluing the small items you have mentioned using rust bluing method is rather tedious drawn out chore. For small items I prefer to "Nitre Blue" them it is quick giving fine deep blue colour without all that carding. But!! it can be dangerous having a molten oxidizing salt Potassium Nitrate at a high temperature, though if you use simple precautions you will have no problems.
Just another suggestion to get to the same end.

The only lessons in my life I truly did learn from where the ones I paid for!