SB,
The USA version '93 124 with 104 HFM/SFI is the first year with the DM , but only in Cal version . Same as the 94/95 E320 vintage, with the exception of the 93 came in both Federal and Ca. versions , with the Ca. version having the built-in Led/Sw and the N59 emmissions DM module. The Fed version did not have this feature, but all 94/95 USA- HFM/SFI 104s had the Cal version w/Led/Sw.
I do have info here that states this difference , but I also have another source that agrees with you on the inception date of DM being 94/94 E320, so I guess if it has a CE , it does, and if it doesn't , it's not there ........