For a diesel wagon, I think your only choice is an '87 300TD.
AFAIK, in later models the wagons are all gassers. The 1996-99 E300D sedans are nice cars; the first two years have the OM606NA engine while '98-99 they added a turbocharger. Another newer alternative are the CDI models from the early 2000's. I think 2005 was the last year of the straight-6 engine, after that it is a V-6. Older cars are somewhat simpler and easier to maintain yourself; newer cars are more complex but have some nice features (yes, I'm oversimplifying).
I had an '85 300D also so I understand the comparisons you are trying to make. The W123 feels like a truck after driving anything newer, even a W124 ('86-'95).
Jeremy
__________________

"Buster" in the '95
Our all-Diesel family
1996 E300D (W210) . .338,000 miles
Wife's car
2005 E320 CDI . . 113,000 miles
My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970