I am most grateful for all the constructive advice about my '91 350SDL.
I will begin tomorrow by contacting MB to see if my car's short block was
replaced since I bought it used at 72K privately. Depending upon that answer, I will then explore my altenatives and options. But, I'm tempted to look at a '96 320S with only 37K miles at a dealership--Smoke Silver. But conservatively speaking, there's an '86 300SDL with only 150K said to be the
'best one around' for $6K. That might be the better way to go.