Aluminum oil pan I'm thinking. Have you thought about taking the oil pan to have it repaired? A welder shouldn't have a problem doing the work. If the damage is in the area of a mating surface then there'll be a need to get a straight edge and file to true the surface. This takes patience.
I hit a curb during a rain storm in Fort Worth in my 71 Alfa Romeo and the lower and upper oil pan got ruptured. I repaired it with epoxy, file, drill, and tap. Was a fairly large area with a mating surface. Took a couple of attempts but it didn't leak. As they say necessity is the mother of invention.
I know of a 98 e300 in the Aurora Colorado upullandpay yard at the moment. Not sure if the pan is still available but you might see if you can find out. Also not sure if this is true in Aurora but when I was down in Albuquerque there were men there with tools that were available to remove parts. That too could be looked into if a pan isn't readily available.
Just trying to give you a couple of options you might not thought of.
BTW while running with a repaired oil pan you could continue to search for a replacement if it's still an issue. But you'll be back on the road in the meantime.
Roddy

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