FWIW, I took one off and found that the spring perch had rusted through, though not badly. I decided to replace them and got two salvage LCAs for $50. They reputedly had come off an 80K w140. They came with the bushings and look pristine as do the arms themselves. Much easier!

Also, for what it's worth, the STAR manual says to the replace the springs by unbolting the inner bushing. I don't know why they say to do it that way, but it works immeasurably easier if you unbolt the outer bushing and lower the LCA that way. It's not the unbolting that's easier, it's the reinstallation—especially if you don't have a lift.