Yes, this part also fits W112 cars. If you just cannot find that part, I would be willing to bet that the exhaust tip for the 220SE Pontons will fit. #000 492 05 14, but it is round.
If you really want to get crazy, I know of an oval exhaust tip but it is for a ......Mopar. I have these on my '70 Roadrunner. Ok, too crazy. But just looking on-line, there are tons of exhaust tips and I bet you could find one that is reasonably close and has a pipe inlet that would work.
Good luck.