The SC 3.2 liter is better known as the Mercedes 112.960 engine.
It was used in the SLK32 (170.466 chassis) from 2002 to 2004.
The C32 (203.065 sedan and 203.265 coupe) used the 112.961 engine (supercharged 3.2) in the same years.
It's essentially the same engine with very minor differences to fit the different chassis.

If you look at your engine cover and other parts, you'll notice that most of them start with the number 112.
The radiator is a 202 part that was borrowed from the 202 chassis (1994-2000 C class chassis).
Mercedes has an interesting part numbering system but it makes it easy to identify parts.