My only reference point is my carb'd 110 engine, so this may not be exactly right.
On the left side of the engine, there is a short tube that runs from the cam/valve cover to the intake manifold. I believe that the equivalent to the PCV valve is in cam cover. It is held in with a plug or screw with a VERY large slot in the top.
There is also a vent off the front of the engine that goes to a tube that leads to a charcoal cannister in the trunk.
I will look tonight in the parts book and manual to see what else I can find.
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe