Each Benz is different depending on shipment/order.
My 420 is just like Brian's, F outside indicator and C for climate control, but
for my 300, the outside AND climate control are both in F (I like that better).
I also noticed that some dashes, i.e. the water temp, can be found in F, while all three of my Benzs were in C. I don't mind that because I know that the boiling point of water is 100C.
Again, I think for the most part, except for the outside temp, you are going to find most things will be in C of MBs, unless an American specified F.
Only diehard Americans need the F.
'89 420 SEL
'90 300 SEL
'84 300 SD (sold it)