4 special tools? Outside of the offset hex bit, you can pretty much get away with what's in your toolbox for working on M117 heads. If all you're doing is retorquing the head bolts, you don't need anything more than the offset hex bit.

Check the Haynes manual. It describes how to get around the special tools... except the offset hex bit.

Sixto
91 300SE
91 300SD
78 450SEL (sold)