I'd be suspicious of a that... First the 3-speed tranny's are extremely reliable. Something must have happened... I'd want to find that out otherwise I'd pass...
I did a rebuild at 110K only because there was a amall leak and I plan on keeping the car for a long time. Now, you have relatively low miles so maybe the car has been sitting up for a long time... the rubber parts will deteriorate...
What you don;t want is a money pit. IF you are as rabid a owner as most of us here, it will be hard to not what to fix the things as they go bad..
1995 E300D 153K
1985 300D 142K (sold)
1979 450SL 122 miles (sold)
1992 500E 127K (sold)
1987 300SDL 132K (sold)
1986 300E 161K (sold)