The article on repairing fogged lenses was very good. I have used the 3M kit with excellent results. PlastX is a miracle in a bottle. Fixes scratches like crazy. Good for maintaining lenses as well. Just wax after use, and never get it on paint.
The link for the double horn stuff doesnt work, says its unavailable. On a side note if you know somebody who works at a paint shop, automotive clear coat works extremely well to restore headlights after you have wet sanded them.