How to maintain a painted copper roof

First of all, thanks for this resource! We recently bought an old house (1860s) with the knowledge that the metal roof was installed somewhere around 1910. We assumed the roof was tin or some other metal since it is painted gray. The paint itself is starting to deteriorate and we had a roofer come examine it to tell us whether we should have it painted again soon. The roofer examined the underside of the roof in the attic and discovered it is actually copper and told us that copper never really needs to be painted since it won't rust. Now I'm left wondering what I should do with the roof in order to keep it as long as possible? Should I remove the old paint and hope for a classic copper finish underneath? Would it be harmful if I just continued to let the paint to peel/chip off? Thanks for your help!