Specs Required for 1989 300D if possible Please?

[steve58]

Hello there, I just bought a 1989 MB 300D W124 chassis (Australian Delivery) from one of my customers with about 470000 kilometers on the clock.
Understandably, this car needs a fair bit of repair work which I will carry out to bring it up to standard. I love the structure and the engineering finess which is present in this vehicle-I have serviced it and kept it going for the previous owner for the last 5 years with no major repairs necessary except the harmonic balancer came loose and in the process destroyed the mounting hub for it where it fits to the crankshaft- unavailable replacement from Mercedes Australia but available from Germany, so I manufactured my own replacement which works fine with thicker retainer washers as well.
I need to source a comprehensive engine service manual, wiring diagram and automatic transmission service repair manual for this vehicle if possible either in book form or on CD.
Interesting thing is that the Mercedes Dealer who I contacted about these requirments said to me that they have never had a wiring diagram for this particular model and the engine transmission details are on microfiche. The engine is a normally aspirated 3 litre 6 cylinder diesel.
Anyone that can point me in the right direction to obtain this Data I would appreciate very much.
Thanks and also thanks for the opportunity to join a very good and informative Forum.
Regards~Steve