As someone who has purchased (2) of the original equipment headlight gaskets, I can tell you that they are very pricey for what is basically two strips of rubber, that seem to like to become detached from the headlights rather easily anyway.

Unless you are concerned with 100% originality, I would go with one of the solutions described above, or in other threads on this topic. I know that if mine ever fly off again, I am not going to bother with the factory replacements...