We just bought a 2002 E320 W210 and failed to get the service records. The car is in excellent condition and appears to be very well taken care of.
My wife stopped by the dealership today to pick up a part for the SLK and some proper 236.10 MB transmission fluid. Just out of curiosity and not to do redundant service she ask if they could look up the "NetStar VMI", vehicle master inquiry, for the vehicle. She said they looked shocked and implied it was 'top secret' info. Ask her why she needed to know and she mentioned we would like to do a transmission fluid, filter change unless it has been recently performed. They suggest she talk to the service adviser.
The SA told her he would NOT recommend changing the fluid as new fluid will cause dirt and worn particles to be suspended and possible destroy the 722.6 transmission.
She called me and relayed the info he gave her. I mentioned that MB also had claimed that transmission was "sealed for life" once upon a time.

Whats the opinion of doing service on a 145K mile 722.6 with unknown history?