The loose rivets on the U brackets of number 4 spring leaf were replaced by using 10mm coach head bolts, cut about 3/16 " longer than the depth of the bracket and spring leaf combined, then peened over (that's fancy for beaten within a inch of its life) and ground back to a smooth surface. The shoulders under the coach bolt head did not need to be removed as they were a perfect hit fit into the existing hole in the bracket.
The brown line indicates where the bolt will be cut down too.
This picture shows the flared out hole in the spring leaf that the peened bolt will be forced into
All done and looking very smart with a coat of primer
The next job will be painting the complete 2 front springs in primer then full gloss black top coat