@JeorgM, the part number F01M101455 is correct.
I paid AU$20 all up for my seal kit at R.Moore & Sons (diesel engineers), local pickup for me in Kewdale WA back in 2014.
Check out the "High Pressure Diesel Injector Pump Seal Replacement" post at
http://forums.mercedesclub.org.uk/sh...d.php?t=105316 (registration required)
Pdf available here:
https://1drv.ms/b/s!AuRLwk8K28oBg8wH...Ij66w?e=bTDqYm
Take note of the warnings regarding the hazardous high-pressure output, over 20000 psi. HP Diesel leaks WILL inject into your skin and may be fatal or result in amputation... that is why most workshops will not do the rebuild without testing facilities available.
The seal replacement is a finnicky job. You will need good tools, good eyes, and a methodical approach.
See attached exploded view of the included parts.