I found that going without my passenger side gasket for a while was causing excess rainwater to get in and it was causing some minor rusting of some metal areas. It possibly aided in the failure of my battery as well, according to the tech that worked on my VX last. I have since replaced that entore headlight assembly and since I had the VX stripped down, I pulled just about every screw, nut, and bolt under the hood and greased them up before replacing.
Also, I pulled the gasket off of the unreplaced headlgith since it was already peeling back and I cleaned the headlight and gasket up really well. Instead of silicone this time, I went ahead and tried a high strength 2 sided tape from 3M. I lined the entire inside of the gasket with it and rethreaded it around the headlight. Let's just say it is so damned strong that I couldnt get it back off when I tried, heh. I appears to be a promising approach.