I didn't want to repair my frame with bolts so i used rivets. I got them from Gig Flats Rivet Co. P.O. Box 100, Big Flats, NY 14814. Phone: (607) 562-3501. Guy's name is Jim Dix, nice folks to deal with. They have a web site:
WWW.bigflatsrivet.com. Go to the website they have instructions on how to install the rivets. I had an air chisel so I purchased their air tool. The install took a little patience but the results where excellent. You can't tell the new rivets from the factory rivets. I purchased 7/16" X 3" round head steel rivets. I think I replaced 8-10 rivets when I restored my frame. Good luck.