I sure am glad that I opened this thread. I also have an 88 300E Five Speed in the garage, but it's only been setting there for a few months. IMHO it will ALWAYS be a worthwhile venture to put one of these jewels on the road regardless of its condition.

Mine is in pretty darn good mechanical condition, but cosmetically it's lacking.

As far as the oil change goes, change it and the filter cold and use a diesel oil such as Chevron Delo 400 or Mobil Delvac. Then after you've driven it a few hundred miles, drain it when the engine is at operating temperature. These oils not only have the zinc additive needed by this engine with no roller cam followers, but also this oil has lots of detergent for soot dispersal which will clean out your set up engine. Chevron Delo 400 15W40 has brought my 300E to the half million kilometer badge mark.

Keep us posted on the project and let me know where to show up for the Manual Transmission 300E club meeting.