There have been more than 400 restorationist groups, all claiming to be the true church. These all go back to the days of the Reformation under Luther and Calvin when some of their followers believed they were wrong in trying to reform the Roman Catholic Church. These were the Anabaptists, but they soon divided into Mennonites, the Amish, etc. The Plymouth Brethren have their roots here, and they are today divided six or eight different ways. Restorationist groups always divide again and again and again, for restorationism by its very nature is divisive.
Reformation is entirely different.
But it has always been in need of reform, even from the beginning. No primitive church was perfect, and they all needed reformation, more or less. In his letters to the churches Paul was a reformer , not a restorationist. He did not want to junk the Corinthian church, believing it to be a false church. It was rather the Body of Christ, and he called it that and recognized it as such, even though it needed reformation.