skuba, bacteria is on everything it would drive me crazy trying to get rid of it. Do you have any idea how nasty the stuff is on the bottom of your purse and most people sit it on the counter in fast food places and on the tables where they eat. There is human waste on the seats in restaurants. That's probably more than you wanted to know. If our homes were bacteria free we would probably get to where we could not go outside because our immune system could not take the germs outside. Just wanted to give you an example. Don't worry about it or it could become a phobia. My friend made her kids stay in their bedrooms alone when they were ill. Now one of her sons does the same with his kids, but he also washes the walls in the bedroom to kill the germs after they get well. In most case mildew in bathrooms are caused by people who turn their showers on very hot and let it run until everything is steamed up. I never have mildew and my mirrors never steam up because I am a hot natured person and want my water cooler than most.

You can remove a lot of stains with a home-made poultice. In my opinion, you want a sealer on marble. I can see how paste wax would work, but I think it would be even less durable than standard marble sealer - more vulnerable to heat, for example. The way to prevent the stains is to use coasters for drinks and trivets for hot items. Sadly, marble is not the durable product many people envision. Here's a link that provides information on poultices: Marble stains

Do you live in an industrial or polluted area? I've heard of copper pipe turning black as a result of excessive sulfur components in the environment. This makes some sense, since artists use potassium polysulfide to blacken copper. Also, back in the old days of rubber insulation on electrical wire, the copper was tinned (coated with solder) to prevent its degradation from the sulfur compounds in the rubber insulation. Do you have any other untreated copper objects outdoors? Are they turning black too? I would be concerned that polishing your cupola will be at best a temporary measure. Once it's cleaned up you might coat it with some kind of clear finish, but then of course you'd never get a patina. The finish will eventually wear off and need to be redone. If worse comes to worst I guess you could paint it. You might have to get it sandblasted or bead blasted first. I'll let others post about good procedures for painting copper, since that's something I know approximately zero about.

So there's no magic solution huh? Just careful and slow. Alright. :) Jem, people still wax brasswinds with car wax! I happen to have a can of car wax for just that. Do people still wax cars? (I wonder if it'll help silver stay shiny--I might try it out on the spare A slide. I don't think it will harm it.) The gold accent on silver was a trendy upgrade in early 20th century. I'm sure that's what this one is. You can still find the ordering options from some of the bigger manufacturers. Lacquer wasn't common until the '30s I think. (Here is a compilation of assorted finish options from much bigger manufacturer Conn for example, if you're curious: https://cderksen.home.xs4all.nl/ConnArticle11.html )