I am working on a helio courier of mine and have built new interior and door panels which were are fiberglass built in the mid 50s. I have made new panels out carbon with a layer of glass where they touch the aluminum skin. I used graphite for weight savings and i am also clear coating them for the sports car look.These panel are riveted with ad rivets right into the exterior skin and the window frames to hold the window in place,they are not strucural as the courier has a 4130 steel cage for its structure. What type of rivets or do i treat these rivits with some kind of insulating epoxy as i buck them?? I am afraid of 15 years down the road of the rivets corroding out or sooner.