W116 Stabilizer bar mount knocking around

I have been hearing a knocking sound from what appears to be the stabilizer bar mount on my '79 450SEL 6.9 with 203,000 miles on it. I began picking in there and found the firewall to have rust. I don't know if the half moon bracket has broken loose from the firewall yet, but after 20 years of living with (and loving) this car, I'd hate to find out that she's no longer serviceable. So my question is: If this mount breaks loose from the firewall while driving, would I loose control of the vehicle or would it just make a horrible banging? The car is in superb condition mechanically and (for the most part) body-wise (meaning no visible rust anywhere on the car). Any help would be greatly appreciated.