I just bought a 1985 300d from the original owner! It has 222,000 miles and is very clean. She did initially get the car serviced through MB then as time passed, she started to go to an independent shop. I can tell the independent shop didn't do as good as a job the MB dealership because I noticed that the oil change tags on the b-pillar had different oil weights, such as 10w-30 and 10w-40. Also, she had 20w-50 oil in the trunk. So much for not using diesel specific oil like 15w-40. The car doesn't smoke when idling and when cruising, but does put out a little haze when flooring it!
There are obvious issues with the car that haven't been taken care of:
1) RPM gauge isn't working
2) The 2 center vents for the air are not blowing any air
3) There is an oil leak under the car, I will have to clean the undercarriage to find where it is coming from.
4) The transmission shifts hard from 1st-2nd
5) There is some sort of burning smell from the engine compartment when running? It isn't oil burning, smells like rubber? Like a belt or something? It is coming from the radiator clutch fan area? This is what scares me!
6) Radio is completely dead, no power
7) I noticed various vacuum lines cracked and leaking, also, some of vacuum lines are completely cracked off? What size vacuum line is needed?
8) The primer pump is leaking, ordered new one.
9) Also, once the driver door is opened, I can hear chiming. It will turn off after some time when the door is closed but randomly chimes again while driving, especially when at a stop??? What is this?

Any help and suggestions would be greatly appreciated!