He is right in a sense... Are you the original owner of that car? He is right in the sense that you won't be able to drive another 70000 miles on a valve body rebuild...
What he didn't tell you is how long you probably can get by... maybe 30,000 miles.
The main question is this... when you shift from P to R how long does it take to engage? How about in Winter? Do you feel that car is slipping in gear?
You see... if the car see majority duty cycle in city, then tranny won't last past 160,000 miles... if the car is majority highway, then it might see
250,000 miles.
The question is this... How much is your local shop want to charge you for tranny rebuild? $2500? Most shop I know will charge you this much.
The other question is How much do you want to save? I know a shop in CO... Silver Star transmission... only MB tranny is what they works on for over 35 years... charges only $1100 last I spoke a while ago for a complete rebuild with exchange... A garage might charge you $500 to put it in...Pep Boys charges $300... Either way, you save $1000 here. You can get the phone number from mbcoupes.com under part supplier.