Glad you found the broken shackles at home. They're not hard to change at home but it's a different matter on the road. Any trailer repair place or competent RV shop should be able to do the job.
This shackle links are a wear item. If one set has torn out, you can be sure that the rest need to be replaced too. The bushings are probably completely worn out too.
Your springs are looking a little tired too. Time to consider replacing them?
Some photos of the job I did last week on my 5er:
Dexter EZ-Flex and wet bolt upgrade.