Where can I get the four rivets I need to remount terminal boards? I get they were brass and solid rounded head rivets. My best measurement suggest 1/4" diam. by 3/4" length. I have been to five hardware stores. I see some online but need to buy hundreds! Would like 6 for a couple of backups. Also how do you rivet solid rivets like mounting new terminal boards on inner fender? I assume someone holds anvil like device on the head side while rivet is tapped to crimp? Denis