Vintage Cars: 1983 Mercedes 380 SL, climate control system, chain conversion

Question
I am looking to buy a 1983 Mercedes 380 SL. has 84K miles. What questions should I ask and what should I check for so I dont have a car with many problems. When does the timing chain need to be replaced? the seller doesn't know if it is a single or double chain. They have a few service records and it has had two owners.

Answer
the 83 is the single timing chain , and in my opinion should be avoided. The '81-'83 had a single row timing chain. Unless it has been converted to double row then I would  pass. Also first year for a poorly designed climate control system. They also only sport about 150 HP, not much for the weight of the car. If you decide to move forward ( there are nice 83's out there)  and it was perfectly maintained, service to the chain is around 100K, but most with the single chain converted to double at a tune of $3000.00 or so around the 75K mark.


What to look for
Rust
does AC/heat work
chain - conversion to double
Hopes this helps