W123 220D, automatic

Hello together, after longer activity with the newer models (S205) I have now gucked into an older model (W123). I probably on Monday a test drive with a 220D with automatic. I looked at it about two weeks ago already. The interior is clean, the trunk as from the factory, no rust recognizable on the body. The engine compartment is not washed and makes a good impression. I wanted to ask once in the round, what I still pay attention to during the test drive. after all, he now has 166 tkm (Bj ’78) down. Has probably remained in first possession for a long time, was passed on in the family, but the niece has no pleasure in it. The H-mark is available, TÜV anyway. I wanted to take a closer look at the typical rust spots of course, but I am grateful for every tip, especially the opinions regarding the automatic. Cost should be the fun 5,300€. Just don’t know if I should really hit him. Wanted him for the Arbe Use itsweg (route: 65km; about 26tkm per year). Garage space is available (at home and work). Thank you very much for your help Greeting Willy