I had a utility trailer's broken springs rehabilitated down here 33-years ago. By a local genius who tempered his own springs. He looked at the trailer springs and muttered "This has got to be a joke".
So, for the next day's project he made a set of springs. Including hangers. Why new hangers?The new springs were considerably wider than the originals. He custom arc'ed them.
Told me to replace the hanger rivets with nuts and bolts but then spot weld them together.
The replacement springs made the utility trailer ride much better empty and same load weight deflection was a lot less. I ended up giving the trailer to a friend and then lost track of both in 2008. He used to stack more than a half-cord of white oak firewood and transport it more than 15 miles over badly rutted dirt road then around 30 miles of highway. Never had a spring issue.
This experience has made me very suspicious of why travel trailer springs break so often.