I don't believe MB would have produced a diesel without an emergency stop lever. It's either disconnected or hidden, like the one in Forced's picture.
I had a 409d with the short lever that Forced pictured but it was under the doghouse which took a long while to remove. In experimenting with quicker ways to shut off the engine, I found that holding a garbage bag over the intake was quite effective. If you have a leak somewhere, hold a plastic bag over it as well as the intake.
I did not try my method at full throttle when vacuum would have been at its highest but I always carried a garbage bag to use in case I had to.

On another note, it surprises me that the engine would run away on crankcase oil with that little amount of overfill. I'm curious as to what other forum members think about that. Are you sure it was running on engine oil? If so, from whence came the oil? If it was coming via the crankcase vent hose, removing that hose should shut down the engine. Was it running at wide open throttle? It doesn't sound like it because there doesn't seem to be enough panic in your posts. I'd investigate to determine whether the problem was elsewhere. It almost sounds to me as if you simply accidentally disconnected the vacuum line to the shut off valve when working at the oil filter and the engine just kept on running when you turned off the key. If this is what happened, it's not the same thing as a runaway.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13