According to my 103 service manual (paperback, original from Benz) those values are correct if 70 Nm equals 52 lbs of torque. This manual lists all torque values in Nm.
"Cylinder head bolts when engine cold 1st stage 70Nm.
Check cylinder head bolts. Each time the cylinder head bolts are tightened they are subject to a certain permanent stretch. If the maximum lenght of 108.4mm is exceeded, the bolts should be scrapped and replaced by new ones."
[This message has been edited by dacia (edited 10-28-2000).]