The sound of a working pendulum clock tells a lot about its condition. Usually when the clock is moved, it would start having problems and it would tend to stop. One of the best ways is to take off the pendulum, and let the movement to work on its own for about an hour. Then level it off correctly, and re attach the pendulum for normal operation.
A video studio is the best place to do all the repairs on artifacts because it could all be recorded on both motion and still cameras. Most on line postings lack quality because of the time it takes for professional shooting. We have worked on watches, cameras, and clocks that if it wasn't for the photos, and footage that we have in our archives, we wouldn't have the time to do it again.
The most interesting mechanism in these clocks is their chime design, and how it could be set to announce the right number of chimes for each hour. More complex than the mechanical chime movement scheme is how it keeps its correlation with the right time by fast forwarding the time while setting the clock. The minute arm is turned by hand without waiting for the chime to finish for each hour, and yet the clock never gets confused.