I friend of mine has an '85 280 SL with 160,000 miles on it and it runs beautifully. Check any euro car very carefully for rust, both outside, under the convertible top well cover, and in the trunk and floors. The engines are great. Some valvetrain "ticking" is normal. You should definitely have the car inspected by a technicial who is familiar with Mercedes and with grey market cars. Any old mechanic is not good enough, it must be someone who is familiar with these cars.