Repair/restoration principles

I'm mostly writing this for myself, but these are my guiding principles when working on clocks and watches:

• Restoration needs to be sympathetic. No overpolishing, no dial replacements unless absolutely necessary. Focus on the mechanical aspects, visual wear is telling a story and is fine.
• No Ammonia. Ammonia makes brass really shine, but it's been known for well over a century that it also damages it. Especially where the metal is under stress, hair fractures will appear. The industry seems to downplay it because "we've been doing it forever and nothing bad happened" and "the contact time is too short for anything bad too happen". But chemistry doesn't work like that, it's not that nothing bad will happen, it's that nothing obviously bad is happening. The reaction starts immediately, it doesn't wait for 5 minutes because the cleaning is only five minutes. Anyway, this rule means less shinier clock plates and wheels, but I want to work with conservation in mind. Even "cheap" time pieces, yes, even dollar watches, have a story to tell and need to be conserved with future generations in mind. Conservation over shininess.

But also:

• At the end of the day, if it is my own watch, I can do what I want. If I want to "upgrade" a cheap watch by jewelling it, for fun or for practice or whatever, that's my decision. Not, say, Reddit's :-)