Well, some CZ 52's have their original phosphate coating, and some were reblued by the Brno arsenal with a semi-matte black "hot dip" blueing. I've seen one that may have been a prototype that had a highly polished blueing that shined like a Smith & Wesson... rich dark blue.
The barrel in my pistol has that highly polished blueing, but the rest of it is phosphate coated (like Parkerizing on US Model 1911's and other WW2 era guns). Only you know which finish your pistol has.
As for whether you need to remove the finish, well, I'm out of my element there. I've never refinished a gun. I'm sure some of our experienced gunsmith types here have an answer for that question.
Scott