From the description of parts used, you have had your transmission rebuilt.
This means that you have the same bunch of metal but the wear pieces have been replaced and all adjustments/set-ups being made.
This means it should work as new. There probably is NO SUCH THING AS "NEW" for anything but current model vehicles. MB sells "Rebuilt" units; basically the same thing you should have recieved. The price you paid is below what any competent MB shop would charge so I definitly would verify that the work was performed.
The problem you have is probably adjustable externally but is part of the job!!! Pre 1985 Diesel trannies needed constant tuning of the vacuum control system. If the tranny is properly set-up internally the repair is simple for an experienced MB tech.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician