After reading and researching a bit more I was able to find a new 2003 Mercedes SLK rear crank end cover.

Also per manual...
Crankshaft oil seal - Rear
REMOVAL
1. Remove the flywheel.
2. Remove the crankshaft end cover bolts.
3. Remove the end cover.
4. Discard the end cover and the rear crankshaft oil seal - WTF? ok I understand the seal, but the whole cover?
5. Clean the engine block and the oil pan gasket surfaces.

Crankshaft oil seal - Rear
INSTALLATION
1. Apply a 1.5 mm to 2 mm bead of Loctite 5203 sealer only where shown on the new end cover.
2. Install the new end cover (without seal installed) and the end cover retaining bolts. Tighten the bolts to 10 N·m (89in. lbs.).
3. Using Special Tool 9100 Rear Seal Installer, install the rear crankshaft oil seal into the new end cover.
4. Remove Special Tool 9100 Rear Seal Installer.
5. Install the flywheel.

So I am assuming I misread the important note...
Note: The rear crankshaft oil seal cannot be replaced separately. The end cover and seal are assembled at the factory and must be replaced as a set.

So this doesn't mean they are a unit it means they both must be replaced at the same time. You can't/shouldn't replace one without the other.