There is a super easy way to remove the old finish. I got this from an antique refinisher.
Boil a pot of water and add two tablespoons baking soda. Put in the brass item and boil a few minutes. Take it out and the old finish will either be gone or can be pulled/rubbed off easily.
Initially, I did not believe the advice and tried lacquer thinner, acetone, paint remover etc. and nothing would touch it.
Decided to try the boiling method before steel wool or other things that would scratch the heck out of the brass.
I have no idea what makes this work but it does.
After removing the old finishing and polishing I decided to just leave it and see how it looked after a year. It looked pretty good. Without the old bubbled finish/protector it developed a nice even patina.