I’ve always like Meguiars Ultimate Compound and Ultimate Polish (I’m only a DIYer though, so a professional may have a different suggestion). And I just saw all your pictures you uploaded this morning. That Bissell Steam Shot comes with a small extension hose and a wider attachment that is useful for cleaning windows. I’m wondering if that would work on all that black mold that you say will come back. However, the steam isn’t as hot once it flows through the extension hose and dissipates through the wider glass attachment. One negative thing about the Steam Shot is that it take a minute to heat up, and then uses the water up relatively quickly in my opinion. Maybe there is a better Steamer?