Mdl 124 4matic
Brother of The Benz, CarolinaMBZ
The only reference I can find to your engine mount extention is in the Service Manual, Engine 103, section 01-310.
There are no torque values, just referenced as item 122.
As MBDOC said, use rule of thumb for the cap screw size.
Happy Trails Beep Beep from The Spiderman in Houston!!!