I wouldn't be overly concerned with the smoothness of the shifts. In fact, if you pull the vacuum line off the modulator and get all good hard shifts that would confirm the the tranny is basically sound. The vac system can be adjusted- many of these cars were sent to an early demise due to minor vacuum issues.If you are interested , feel free to check in over at peachparts.com diesel discussion and get smart(er).Rick
peachparts.com diesel discussion and get smart(er).
A similar condition '82 VW Rabbit would be worth considerably more.
FWIW, I didn't go for the Mercedes. I finally traded the truck for an 81 Jetta diesel and $1000.