Professional Help (no link)
Very few clockmakers actually make clocks. Most are repairers and most are enthusiasts not commercial businesses. Beware of high street jewellers and one man bands, most lack the bredth of experience of turret clocks and often have very limited resources. Because of that, they offer what they can do, and not what a clock might need. The level of work can be close to DIY and ignorance of health and safety regulations which are different from common sense. Try the Museum Services Directory if you are looking for serious quality.
More jargon. One useful definition is it is the quality of work and the way of doing it, needed to qualify for grants for conservation work. It is an international standard and for old clocks precludes the use of modern fixings except for safety reasons, no modern fabrication techniques such as high performance glues and high tech welding etc., and takes into account the building and use of the clock. Ask yourself the question how did the original clockmakers do it, and copy that. It is very easy to "improve" on old clocks, resist the temptation, and be a good custodian for the future.
Who indeed. Use a search engine for key words such as a famous clock near you, like any other service, local recommendation is still the best but do not be afraid to use clockmakers from outside the area, some of the big firms operate nationwide. This site is for information only but if you want to email comments feel free to email firstname.lastname@example.org