Oh, another thing to see is whether or not the car has the Nasty Trap Oxidizer on the exhaust line, look for a football shaped metal thing just to the right of the engine, sort of to the rearwards of the air filter box, its hard to miss. If its there then that needs to be replaced with a straight pipe under a factory recall. Be sure to check to see if you can feel any play in the turbo impeller, side to side or front to back.
And its really great to hear your going to rescue the 124 300D, a great automobile!

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!