The 124 Service CD gives the following steps for tightening the head bolts:
Measure all bolts to insure they are less than 163.5 mm long.
Clean and dry bolt holes.
Lubricate bolt threads and washers with motor oil.
Torque in following stages (ALL head bolts):
1) 55 nm
2) 90 degrees
3) 90 degrees
I suspect the "1-10" in your book is a misprint.
I'm not sure what you mean by adjust the timing chain tensioner-- it's self adjusting. However, you need to disassemble the tensioner before reinstalling it so as to prevent the plunger from being hyperextended. Install the tensioner housing to 80 nm of torque. Then install the plunger (you may need to tap it into place with a suitable drift/punch), spring and spring filler thing-a-ma-jig before installing the Allen head plug to 40 nm of torque. MB specifies using new sealing washers on the tensioner housing and Allen head plug.
Also note that certain of the cam sprocket attaching bolts (there are several variations of these) are stretch bolts and should not be reused!
'93 190E 2.6 Sportline