Re: Cleaning/Polishing Portlights
Looks like they are aluminium. If so, the only way to keep them looking good without frequent polishing is to have them anodized. You'd have to remove and completely disassemble them for that - remove the glass and so forth. Failing that, they look quite smooth so you could try polishing them with Autosol metal polish - I find it's the best.
I, myself, personally intend to continue being outspoken and opinionated, intolerant of all fanatics, fools and ignoramuses, deeply suspicious of all those who have "found the answer" and on my bad days, downright rude.