Hi
I did a thorough search last night and here is the result:

The charger number for the Garrett T3 charger used in the OM 617951 is:

T0301 and the parts list is 465228-0003

All info is here:

Garrett Model TAO301 Repair List - 465228-0003 reference - Turbos - TurboMaster

comparing it with the part sheet for: 454039-0001 which is on offer

Garrett Model TBO390 Repair List - 454039-0001 reference - Turbos - TurboMaster

I realised quickly, that both sides are different, - so this is not the way to go.

But I found a good offer for a replacement cartridge to302 Using the same site again, I figured out, that only the compressor wheel is different.

The 300sd wheel is: 409096 - 0008 the other one is a 409096 - 0014.
Changing them is no problem as in Garrett the Compressor wheel and the turbine wheel are balanced individually.

The Mercedes compressor wheel can be got separately on EBAY.
I approached the workshop who has TO302 on offer, if they can exchange the compressor wheel for me free of charge.

BTW. Replacing the complete cartridge then can be done less than 200 $ for parts.

Regards,
Hans Weitbrecht