Hello stayalert
Presume you have a W123 300D.
A little junk yard shopping should help answer some of your question, seeing it in person is better + you may find some of the parts you need, cheap.

Some pictures of your engine, interior, trunk and exterior would help us guess at what may be missing.

__________________
ASE Master Mechanic

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D

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