A complete records car that needs nothing would probably fetch $6-8000.

I don't think the vacuum pump can be rebuilt. Replaced is more like it.

The original cylinder head is susceptible to cracks if overheated. Ideally the records will indicate that the cylinder head was replaced. If not, keep an eye on the temp gauge. 'Needs head gasket' is not a good caveat on these cars.

The front end will need a $1000 refurbishment if it hasn't been done. It's not mandatory but it will restore 230K miles of looseness and clunks.

Who makes 20W-50 synthetic?

Sixto
93 300SD 3.0