Anything can be repaired. I would say listen to your mechanic though. If you are having a problem with suspension attachments your have severe rust. It is like cancer; it only gets worse. It can not be fixed, it can only be put off.
There are too many nice bodies and in a 116 model they are not going to cost much. Put your efforts into something that will stay with you as you restore it.
Bosch Master, ASE Master, L1
33 years MB technician