That's one rare car because MB didn't offer the E320 until 1994. Possibly a 300E with the wrong badge?

The M103 engine of the 300E is claimed to be bulletproof. It's easy to work on as MB engines go. That said, replacing an M103 water pump is about as difficult as it gets on an MB. On the other hand, it's much easier on the chain and few bother performing specific maintenance on the chain. Valve seals and guides are a weak point on eary M103s so plan on a valve job if one hasn't been done.

I can't speak for the rest of the W124 other than to say that the suspension is nothing like the suspension of a W126. The ACC system is similar but most tasks involve taking the dash apart where they only require long arms in a W126.

Sixto
95 S420
87 300SDL