All the ones I have, and its about 20, have the rivets peened down, or riveted! Never seen any fancy fasteners. Back in the day they probably had a press that whacked the rivet in one hit. I myself use nails, being soft enough to peen easily. To hold the scales on securely I use Epoxy, keeps things from moving. Glue on one side. Drill from inside to outside. Glue on the other half,, drill from outside to outside. Want to make sure they stay tight? Drill each at an angle from each other, locks the scales on without using epoxy.