I may have tracked down a local 4 speed 1978 240d with a suspiciously low mileage of 140,000 kms (about 89,000 miles). Sounds too good to be true so I am going to take a look.

I have a 300sd so kinda know some of the basic things to look for but .. any specific gotchas I should be looking at in this vehicle?

I don't know the 123 chassis style at all.