from what i gathered in various threads there are three different kinds of head gaskets out there for the M104. i think MB has an improved design (look for a Steve B thread on this), and then there's Goetze, which i believe is also sold as OEM, and which has had a good write up or two and there's a third kind which i don't recall anything about. use of either of the first two appaears to prevent recurrence in reported cases.
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"