'Vienna Regulator' is one of those things, like a 'Hoover' which started out as a specific object and over the course of time has been adopted to refer to a whole group of similar objects.The original "Vienna Regulators" were made in Austria by the master clockmakers. They were very high quality clocks, weight driven, hand made and of simple style. They were very good timekeepers and were often used in public buildings.
You are not likely to find one of these!
In "collectable clocks" it says "What do appear frequently , and are quite erroneously referred to as vienna regulators are the later german made copies. They neither come from Vienna nor are they precision timepieces."
From the 1850s clock factories in Germany started to make these copies of the superior Austrian clocks. Some of these copies, particularly the later ones, were spring driven. The quality varied a lot. Some are held in high esteem, (Lenzkirch for example are good and produced well over a million clocks) whilst others are just mass produced 'things'.
Most of the original Austrian regulators had relatively simple but attractive casework, but the copies are often more ornate and to my eyes tend to be over decorated with turned side columns, a heavy pediment, often carved and with animals and such like as embellishments. The pendulum is a visible feature, and while the originals had operational compensated pendulums the copies often have complex appearing but fake compensation.
One interesting point is that although a "seconds hand" is sometimes fitted, it seldom records true seconds as most of this type of clock have a beat of 80 rather than 60! Obviously it was included purely as a decorative feature since the pendulum itself shows if the clock is running.
Having told you what the experts think of these clocks I can now tell you that despite the adverse comments they are still extremely popular and are sold at what I consider to be quite high prices. The Shentons, in my favourite book