The only hope that I can offer on your trans question is that in the section on replacing the fluid in manual transmissions in the 250/280 CD, it shows the same capacity (1.6 pints) for bodies 108, 114, 115, and 123.

Does this mean it will fit? No. But it is mildly encouraging.

My impression is that in these year, MB used the same basic transmission and changed the engine plate to get them to mate to specific engines.

Chuck