Many MTs use the engine crankshaft as a forward support for the input shaft. Since the crankshaft and input shaft turn at different speeds sometimes, there is a bearing between the two shafts. IIRC all OM616s and possibly all OM617s have provision for a pilot bearing so it's just a matter of popping in a pilot bearing during conversion. Such could be the case with the M110. Either someone who knows can confirm or you have to wait until you pull the tranny off the 280S to see for yourself.

Sixto