While not correct, I found some small aluminum bolts with big heads on them at Lowe's in the specialty hardware section that I was able to file and polish the heads down (they had a very shallow straight blade screwdriver slot in them). They mimic the rivets very closely. Once the gutter is mounted on the firewall and the wire installed inside of it, I don't think anyone will ever know the difference. Now if you're working on a 1,000 point concourse restoration, then this probably wouldn't work for you...