Our copper rivets from Kentucky are applied with a cast iron foot press that is circa 1930’s. Found in a mid town Manhattan small machine shop. It didn’t work and needed to be restored. I took a chance and bought it. I was able to fix it and know it works great. The best rivets are the kind that have a post and ring. The ring sits at base of the post. The foot press cause the post to mushroom over the ring. This permanently attaches the rivet to the jean. The common modern way is with a cap instead of ring which occasionally falls off like most caps!