Flywheel is the issue. You want to discover if donor car (220/240D?) flywheel will fit your 250 engine.

Maybe later flywheel, European import from standard shift 300D / chassis #115 or #123 will work.

Btw, issue with flywheel is ballancing.... most people ballance newly introduced flywheels at high tech / race shops when making conversion of MB from automatic to standard.