Ever figure out what to do?
I had a similar problem..when riding my 82 seca home from buying it the headlight fell out along the way. After picking up what I could find of it, I held it in place with a tube of J/B stick weld,"perfect for everything", then using filler I filled in the space all the way around the lamp..then smoothed it down starting with a rough grit sand paper working to smooth....then painted the entire housing.
Downside is I cant get to the wiring with out ripping all my work apart...so Im looking around for a new head lamp assembly.
But from my other post I was sent this. Courtesy of yamahead