Peter, I bought both from Mercedes. I can check diameter on Friday.
What the EPC is saying:
The straight line, A1299970282, was made the same for both Europe and America for engines 129 980, 981, 982 and 130 980, 981, 983 (US) and 130 980, 981, 983, 984 Europe.
The bent one, A12907000632, was made for exactly the same engines.
So you just need to check if you have one of these engines in your sedan and if so, it should fit.