As stated you need to understand why you are polishing this or that. It can get in tuning the mechanism. Many locks are slapped together from rough unfitted cast parts. The problem is that certain relationships need to be properly fitted for decent function.
I spent time yesterday on a pedersoli yeager lock. Just about everything was sub standard. The tumbler fit in the bridle and lock plate was very sloppy. The bridle was too tight to the plate, the bridle screw needed to be loose to allow the tumbler to rotate. The full cock notch was set an angle that caused the cock to move foreword when you pulled the trigger, before it released. That was overcome with a massively over powered sear spring. The sear screw was way too small and the sear nose was to short. The short sear made it so only short flints clear the frizzen at half cock. The pan did not fit the frizzen at all, there were large gaps. There was no clean up of the milling machine burs before sandblasting and case hardening. It is the worse expensive lock I have ever worked on. It can all be fixed with enough work and knowledge. That work was made more difficult by the case hardening.
Sometimes polishing alone is not the solution. A sloppy poorly made lock will not be made better with polishing alone. Did the lock fire the gun before I worked on it? Yes.. Did it do so safely and efficiently, no. After making parts and fitting others, it is safe and works better. I did cut my losses and stop there. To make it right would require many new handmade parts. The time required is not justified in this case. A better solution would be to get a new quality lock kit with a blank plate and start over. Franky, based on reputation I was shocked at how awful the lock was.