Cees:
You are slightly off the mark. As told to me by a very good German Mechanic in Sarasota FLA, The best mechanically sound M/B cars are prior to 1995.
After that year they fall apart after 4 years, the warranty period.
He has seen a letter from M/B directly from the factory which states this fact.
I have owned Diesels since 1972, and they are the best, as long as they are properly maintained you can obtain about 500,000 miles at least.
I have owned and still have all these cars, but some of them are ready for the junk yard. Living in New England. Salt destroys these cars even though you wash them every time you are in salt.
They are, 1968 200D Junk (extremely noisy but a great car, W110), 1972 220D W115, still in use, 1974 240D W115 117, Junk, 1977 240D W123, Junk, and still in use is my 1982 and 1983 300SD, W126.
The car mentioned above is W115.114 300D, which I never new existed. Looks like a good car, check for rust underneath, put in up on a lift.
You can verify this by going on the EPC M/B parts catalog, cost is $25 per a year. You can verify all parts for all M/B cars all over the world.
These cars that old do not go for much money, at least in the East.
I would not pay any more than a $1,000 for it.
I can buy my 300SD's for about $1800 to $2500 around here.
So if this car does not have any rust, go for it even with the high mileage.
But do not pay $7500.
Now the other point made was about how would it look with your other M/B cars.
They look great.
When I line up my 1968 200D, 1972 220D, 1974 240D, 1977 240D, 1982 & 1983 300SD, 1967 250SL & 1971 280SL side by side, they are fantastic.
You look at the grills side by side and they are fantastic.
Then you know you really are a M/B owner.
By the way, the 1972 220D was the only car I bought new. Picked it up in Stuttgart Germany at the factory.
All the others were bought used.