Look for a plastic cover, its there, on the right "wall" of that legroom.
Sorry, i seem to have a "bad English day" today :P
it has 232 hp.
1974
Inside the fuse box which is under the hood adjacent to the brake master cylinder.
Very carefully
Look in the car manual
Group Size 49
Just cost me $564 for 2008 GL 450
Firing order sl 450 v 12 engine
firing order for 73 mercadies 300sel 4.5
280 bhp not sure about hp. Have this car, Actually 2 I LOVE THEM
I'm not sure about the location for your 300SD, but I have a 1979 450 SLC and the fuse box is located underneath the dash on the passenger's side -- to the right of where the passenger would place his feet. The fuse box diagram should be glued to the back of the door that opens to the fuse box.
Sold for $38,300 brand new. In average retail condition it's worth about $12.900 now. Can't be to rare.