Finally back in town... Amuso, your 004 545 46 32 is an Ignition Control Box (replaced by 005 545 87 32).
The other part numbers you listed don't seem to be the standard format... but the only control units I see listed for your car are the KE Control Unit and ABS Control Unit. So if you've got ABS brakes that should be that mystery unit.
Another update on my sudden-death problem... I ended up replacing my MAS control unit during my trip, not for the sudden death problem but due to my A/C going out. Both the A/C and fuel pump relay functions are handled by the MAS so I'll see if that fixes the sudden-death thing too.
As feared, it wasn't a cheap part -- $350.
1999 E320 Wagon