If in a fuse hurry
Your NAPA guy is wrong. You can still get the ceramic fuses from Auto Zone as well as your local O'Reilly Automotive if you have either of these parts places in your locale. If time isn't a problem, like was mentioned, Fastlane as well as Mercedes Shop both carries them OEM.
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan