Battery frame, tray and upper - satin finish black (may also be termed semi-gloss)
radiator - satin black
Air filter box - satin black
Cooling system reservoir - satin black
Engine Compartment - body color, same as car but not buffed out (have been some recent posts on this)
Grille - Satin black
Wheel wells - Body color , my 280 SL is fairly glossy, but may not have been buffed out
Automatic transmission shield - body color, and there should be the body number stamped on it
Rocker panels - very dark grey (use the search function, a lot has been typed about on this subject) Same as the trunk
Front and Rear suspension - satin black
Petrol tank - black, but not sure if satin or matte
Bottom inside the car, body color
bottom behind the seats - body color
firewall - body color, not buffed out
convertible cap space, black satin
Relays in my car are natural finish aluminum, but I think some were in black (early cars?)