In a 1978 Haynes manual on the 230, 250 and 280 SL's, the camshaft sprocket bolt torque is indeed listed as 80 Nm, or 58 ft lbs. The crankshaft pulley bolt is listed as 207 Nm, or 150 ft lbs.
The latter gave me a problem as I have no torque wrench that will go to that value, just 100 ft lbs. There's 3 dished washers between the bolt shoulder and the pulley. I stacked them as per the manual, that is first on pulley is "point" out, then second is point in, third point out, then bolt shoulder. This gives the stack with the largest thickness. With a cheater pipe on my wrench, I tightened until those washers were collapsed, that is no space between the second and third, the first and the pulley, and the third and the bolt. I hope this works!
Ron