clock cases which were made by Royal Bonn in Germany had mechanical
works that were usually manufactured in America by Ansonia Clock Company.
A genuine Bonn porcelain case is marked as such.
cases also imported from Germany often had movements made by American
clock manufacturers. Dresden clocks are also marked with the Dresden
name. Not all porcelain cases were marked. Many cases do have manufacture's markings and therefore, it very difficult to determine who made the clock.
to Identify your Clock