Hey all, just an update for any interested parties.
I emailed ZF in Australia and the told me all 6HP19 internals are the same, EXCEPT if it comes out of a 4WD(AWD). I purchased a ZF6HP19 from an E90 (N46 engine), stripped the internals and put it into my ZF6HP19 case. (E60 with M54 engine). Changed the mechatronics block and pipe seals and reassembled. It went fine, no dramas and very smooth. Happy days. Hope this helps someone.