When are they too far gone?

When do you cry uncle on the rear springs guys? I was going to work on them and after closer inspection they look like they are hurting pretty bad, There are 5 leafs and one of the small ones is broken. Also notice all the clamps on the front of the springs, makes me think theres trouble. I think with the car having air shocks on it already is a sign the springs may have seen better days.
Should I rebuild or just replace? Are 5 leafs stock? What would you guys do? Thanks
Tony