One thing you can do for the rust,if it's not to bad.Take 4 or 5 0000 steel wool,Use Hoppies # 9,saturate steel wool,and rub LIGHTLY.Do this every day for 30 days.Have seen barrels,firearms,that looked bad,come out looking Good.If you do a little each day,you will not remove blueing;just the rust,hope this helps