Hello,

Background: In my new-to-me 2013,  am replacing the exterior light over the propane tanks. I bought the recommended light from Scamp, which looks identical to the old one. Lo and behold, once I got the existing one off, there are pre-existing "extra" holes in fiberglass, as if the light had been replaced before. I need to drill new holes, as none match up, and I am worried about structural integrity of the fiberglass, as my first rivet (alumininum) did not successfully compress and broke through the fiberglass. I can patch and try again, but the more holes there are in that limited space worries me.  These are blind pop rivets, so no access to the back to reinforce with a washer. 

Anyone with thoughts, or previous experience?

Thanks!