I am speculating here, but I would think that the sealant that glass shops use for dual pane windows would be a good choice. It is intended to make a pliable, moisture-proof seal to keep condensation out of household windows. I am also wondering if you could flush them with an inert gas to eliminate any water vapor that is present in the air. I also wonder if there is a way to incorporate a desiccant somewhere, to help remove any vapor that may ever get in there. If these things work, we may have a (hopefully) permanent solution for the louvers.
As far as what paint to use, I really donít know. Again speculation leads me to think that ĎImroní paint may be a good choice. It is a catalyzed paint used for aircraft exteriors, so it sure can take a beating, thermally & otherwise.
Please let me know how/if these ideas work!
Also, Iíd like to know how difficult it was to remove the louvers & what the steps involved are.
P.S. How do you like your 5.0? (Dumb question, huh?) You seem to be an SLC addict like me Ė Iíve also got a U.S. spec 450. Iíve owned four over the years.