I would =>
Check the condition of your tyres!!!
Then
engine oil and filter
coolant
transmission oil and filter
differential oil
brake fluid
power steering fluid and filter
fuel filters
air filter
clean check and adjust front wheel bearings (for the rear you have to hope for the best really as they are difficult to get to)
check for oil in the axles
Most importantly though check the overall condition of the car. Don't just limit yourself to the mechanical components. Look at the water drains and the rubber seals and make sure there that water isn't getting into the car. W123s can rust and rust and rust. I think that rust is the number one killer of these cars.
After driving for a few weeks I'd change the engine oil and filter again.
Check the condition of your tyres!!!
Then
engine oil and filter
coolant
transmission oil and filter
differential oil
brake fluid
power steering fluid and filter
fuel filters
air filter
clean check and adjust front wheel bearings (for the rear you have to hope for the best really as they are difficult to get to)
check for oil in the axles
Most importantly though check the overall condition of the car. Don't just limit yourself to the mechanical components. Look at the water drains and the rubber seals and make sure there that water isn't getting into the car. W123s can rust and rust and rust. I think that rust is the number one killer of these cars.
After driving for a few weeks I'd change the engine oil and filter again.