It appears that my '92 (and presumably MB FRAU's '93) doesn't have the Fuel Pump and A/C relays, at least not in the same place (see below, inspired by your photo).
I do have a few more mystery control boxes, though.
From what I can tell, your two control boxes are the KE Control Unit and possibly the ABS Control Unit. If you've got the part numbers for them I could look 'em up.