Jake,
I was replying to Dave's post re. his carbon mast on the HT.
You need to be cautious using rivets in carbon. The compression & expansion force can lead to cracking of the laminate around the hole. Drilling & tapping for a suitable sized machine bolt works quite well in even thin carbon. I use thickened epoxy in the tapped hole and around the base of the fitting for extra insurance.
Tiger mast is aluminum.
are the hats plastic?